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223 Genrtic~a 83: 223-234, 1991, 0 I99 1 K~IIIW Acadwic Publishm. Prinled in the Netherlands. Chromosomes of Australian lygosomine skinks (Lacertilia: Scincidae) II. The genus Lampropholis S. C. Donnellan School of Biological Sciences, Macquarie University, New South Wales 2113, Australia Present adress: Evolutionary Biology Unit, South Australian Museum, Adelaide, South Australia 5000, Australia Received 28 June 1990 Accepted in revised form 11 December 1990 Abstract Standard and C-banded karyotypes of 101 specimens of the skink genus Lampropholis, including all but one of the 10 described species, were examined to assess the value of karyotypic data for resolving current systematic problems with Lampropholis. Diploid chromosome numbers were mostly 30 except for two forms with 28 chromosomes due to a reduction in the number of microchromosomes. The majority of interspecific chromosome changes were due to pericentric rearrangements. Apart from karyotypes referable to the described species, four distinct karyomorphs were found. Individuals possessing these karyomorphs could not be readily assigned to any of the described species. Introduction Greer (1979) divided the Australian members of the scincid lizard subfamily Lygosominae into three groups: the Egernia, Eugongylus and Sphenomorphus groups. Lampropholis Fitzinger, a genus included in the Eugongylus group, has had a chequered systematic history. The genus typifies the ‘intractable small brown skinks’ that have troubled systematists since Boulenger’s time late last century. Greer (1974) ressur- ected Lampropholis from the synonymy of Leiolopisma Dumeril and Bibron to accomodate the type species L. guichenoti (Dumeril and Bibron) and three other species previously residing in Leiolopisma: L. challeng- eri (Boulenger), L. delicata (De Vis) and L. mustelina (O’Shaughnessy). A further six species have been described recently (Greer & Kluge, 1980; Ingram & Rawlinson, 1981), but documentation of species di- versity is still inadequate with several forms awaiting taxonomic appraisal (Mather, 1990). The relationships of the species constituting Lam- propholis remain unresolved. Greer and Kluge (1980) recognised the challengeri and delicata groups within Lampropholis. Subesquently Ingram and Rawlinson (1981) were unable to assign with certainty L. caligula to either group. The lack of resolution in systematics of Lampro- pho/is is due in part to the paucity of phylogenetically informative morphological characters. Karyotypic analyses have been found to be useful in reptiles for delineating species and for interpreting relationships at higher taxonomic levels (Gorman, 1973; King & King, 1975; Bickham, 1983; King, 1983a). The present study was undertaken to assess the value of karyotypic data for investigating the systematics of Lampropholis. Materials and methods Table 1 lists the 101 specimens of Lampropholis studied, their geographic origins, and the chromo- some analysis applied to each. Of the 10 described species, only L. tetradactyla was unavailable for study. Specimens were deposited with the Australian, Queensland and South Australian Museums or re- tained by the original collectors as listed in Appendix 1. Karyotypes were prepared from heart and lung fibroblasts cultured in Hams FlO medium supple- mented with 20% foetal calf serum. Heart and lung tissue was explanted onto coverslips in Leighton tubes. Outgrowths of fibroblasts derived from tissue

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Page 1: Chromosomes of Australian lygosomine skinks (Lacertilia: …aerg.canberra.edu.au/library/sex_general/1991_Donnellan... · 2006. 2. 20. · 223 Genrtic~a 83: 223-234, 1991, 0 I99 1

223 Genrtic~a 83: 223-234, 1991, 0 I99 1 K~IIIW Acadwic Publishm. Prinled in the Netherlands.

Chromosomes of Australian lygosomine skinks (Lacertilia: Scincidae) II. The genus Lampropholis

S. C. Donnellan

School of Biological Sciences, Macquarie University, New South Wales 2113, Australia Present adress: Evolutionary Biology Unit, South Australian Museum, Adelaide, South Australia 5000, Australia

Received 28 June 1990 Accepted in revised form 11 December 1990

Abstract

Standard and C-banded karyotypes of 101 specimens of the skink genus Lampropholis, including all but one of the

10 described species, were examined to assess the value of karyotypic data for resolving current systematic problems with Lampropholis. Diploid chromosome numbers were mostly 30 except for two forms with 28 chromosomes due

to a reduction in the number of microchromosomes. The majority of interspecific chromosome changes were due to pericentric rearrangements. Apart from karyotypes referable to the described species, four distinct karyomorphs

were found. Individuals possessing these karyomorphs could not be readily assigned to any of the described species.

Introduction

Greer (1979) divided the Australian members of the

scincid lizard subfamily Lygosominae into three

groups: the Egernia, Eugongylus and Sphenomorphus groups. Lampropholis Fitzinger, a genus included in

the Eugongylus group, has had a chequered systematic history. The genus typifies the ‘intractable small

brown skinks’ that have troubled systematists since

Boulenger’s time late last century. Greer (1974) ressur- ected Lampropholis from the synonymy of Leiolopisma Dumeril and Bibron to accomodate the type species L.

guichenoti (Dumeril and Bibron) and three other

species previously residing in Leiolopisma: L. challeng- eri (Boulenger), L. delicata (De Vis) and L. mustelina

(O’Shaughnessy). A further six species have been described recently (Greer & Kluge, 1980; Ingram &

Rawlinson, 1981), but documentation of species di- versity is still inadequate with several forms awaiting

taxonomic appraisal (Mather, 1990). The relationships of the species constituting Lam-

propholis remain unresolved. Greer and Kluge (1980) recognised the challengeri and delicata groups within Lampropholis. Subesquently Ingram and Rawlinson

(1981) were unable to assign with certainty L. caligula to either group.

The lack of resolution in systematics of Lampro-

pho/is is due in part to the paucity of phylogenetically informative morphological characters. Karyotypic

analyses have been found to be useful in reptiles for

delineating species and for interpreting relationships at higher taxonomic levels (Gorman, 1973; King &

King, 1975; Bickham, 1983; King, 1983a). The present study was undertaken to assess the value of karyotypic

data for investigating the systematics of Lampropholis.

Materials and methods

Table 1 lists the 101 specimens of Lampropholis

studied, their geographic origins, and the chromo- some analysis applied to each. Of the 10 described

species, only L. tetradactyla was unavailable for study. Specimens were deposited with the Australian,

Queensland and South Australian Museums or re-

tained by the original collectors as listed in Appendix 1.

Karyotypes were prepared from heart and lung fibroblasts cultured in Hams FlO medium supple-

mented with 20% foetal calf serum. Heart and lung tissue was explanted onto coverslips in Leighton tubes. Outgrowths of fibroblasts derived from tissue

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224

Table I. Specimens of Lampropholis examined. S= Standard karyotype. C= C-band karyotype, Qld = Queensland, N.S.W. =New South Wales. Superscripts l-7 indicate the presence of

chromosomal variants as follows I: 2 individuals heterozygous for

pericentric rearrangements of pair 8 (het.peri.8). 2: 1 individual heterozygous for heterochromatin addition (het. add.) to pair 9

and I heterozygote for het.peri.8. 3: I heterozygote for Robertso- nian rearrangement of pair I or 2 and I heterozygote for het. add.

to 9.41 I heterozygote for het. add. to 9 and IO. 5: I homozygote for peri. 8. I heterozygote for het. add. to 9. 6: I heterozygote for het.

peri. 6. 7: I het.peri. 6.

Species Male Fe- Locality male

s cs c

L.amicuia I -

1 -

L. basiliscus I I 1 I

L. caligula - 1 I

L.challengeri I I 1 I I 1 I

I I -

I - I I

I I I

L.czechurai 2 I -

I -

L.delicata 2 2

I

I I I I I

I I -

I 2’

I -

2 I 1:

I I - 2 3’

I - 2 - I -

I 2 24

I - 3 2 2 2’ 3 -

Ih I I I I’

2 - 1 I I

2 -

Mogill S.F., Qld.

Rainbow Beach., Qld.

Charmillan Ck., Qld.

Barrington Tops, N.S.W.

Randwick, N.S.W. Neutral Bay, N.S.W. Bellevue Hill, N.S.W.

near Brinerville. N.S.W.

Mt. Warning, N.S.W. Alstonville, N.S.W.

Mt. Glorious, Qld.

Charmillan Ck., Qld.

Millaa, Millaa, Qld.

Lauceston, Tasmania

Marble Range, S.A.

near Port Lincoln, S.A. 25km N. Avenue, S.A. Eltham, Victoria

Bondi S.F., N.S.W. near Nowra, N.S.W.

Coogee, N.S.W.

Pymble, N.S.W. Neutral Bay, N.S.W. Watagan S.F., N.S.W.

Doyalson, N.S.W. Myall Lakes, N.S.W. Werrikimbe N.P., N.S.W.

Carrai S.F., N.S.W. near Brinerville, N.S.W. Cambridge Plateau. N.S.W.

Wiangarie SF., N.S.W. Scarborough, Qld. Connondale Range, Qld.

Bunya Mtns., Qld. Granite Ck., Qld. Rockhampton. Qld. Byfield, Qld. Mt. Morgan, Qld.

Species Male Fe- Locality male

s cs c

L.guichenoti - I near Glare, S.A.

1 I 2 2 Pymble, N.S.W.

L.mirabilis - I Cape Cleveland, Qld.

L.mustelina - I Greenwich, N.S.W. 1 Bellevue Hill, N.S.W.

I I - Wentworth Falls. N.S.W. I near Barry, N.S.W.

L.sp. A I Kuranda, Qld.

5 I - Charmillan Ck.. Qld.

L. sp. B I 3 Mt. Bartle Frere, Qld.

L. sp. c 2 - Connondale Range, Qld. 2 - Granite Ck., Qld.

I - Bulburin S.F., Qld. 3 3 I I Crediton Ck., Qld.

L. sp. D I I I I Mt. Glorious, Qld. I 2 Mt. Nebo, Qld.

pieces were harvested in situ on the coverslips. Three

replicate cultures were initiated on each specimen. Cultures of most species grew adequately at 3O”C,

except those of L. challengeri, L. basiliscus and L. czechurai which grew successfully only at 24°C.

Meiotic preparations were made following the technique of Gorman et al. (1967), excepting that

hypotonic treatment was for 25 minutes in 0.53% KCl. Cells were harvested according to the procedure of

Donnellan (1990). Preparations were stained with

10% Giemsa for two minutes. The C-banding method of Sumner (1972) was employed.

Results

Diploid numbers were either 30 or 28 (Table 2) with

nine macrochromosome pairs @airs one-nine) and either five or six pairs of microchromosomes. One individual of L. delicata had 29 chromosomes due to a Robertsonian rearrangement among the macrochro- mosomes (see below). With the exception of this individual the six largest pairs of chromosomes were

invariant with the first five being metacentric and the

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Table 2. Summary of karyotypic variation in Lampropholis. Only the chromosome pairs showing variation are presented. M: metacentric, SM: submetacentric. A: acrocentric, T: telocentric.

Chromosome pair

basiliscus an~icula caligula challengeri czrchurai delicata pichenoti tnirabilis mustelina sp. A sp. B sp. C sp. D

sixth submetacentric. Variation was confined to the remaining chromosomes (Table 2) and is detailed along with the C-banding pattern of the whole karyotype in the individual accounts which follow. For comparative purposes the karyotype of each species is compared to that of L. basiliscus (Fig. l), which has the karyotype with the commonest mor- phology for the variable chromosome pairs.

In addition to the karyotypes of the described species of Lampropholis, populations with four distinct karyomorphs were found. Individuals with these

distinct karyotypes could not be assigned readily to any described species and herein are assigned pro- visionally to the taxa Lampropholis sp. A to D.

Lampropholis basiliscus Ingram and Rawlinson. 2n=30 Pairs six and seven were submetacentric, pair eight acrocentric, and pair nine and the largest pair of microchromosomes were telocentric (Fig. 1). The remaining pairs of microchromosomes were either acrocentric or telocentric. The fourth pair of macro- chromosomes and two pairs of microchromosomes had prominent, centromeric C-bands (Fig. 5a). There were 'grey' telomeric C-bands on the long arm of one of the two largest macrochromosomes.

Lampropholis amicula Ingram and Rawlinson. 2n=30 The standard karyotype of L. amicula differed from that of L. basiliscus in having an acrocentric pair seven, metacentric pairs nine and ten, and in the largest microchromosome pair being metacentric (Fig. 2a). There was insufficient material for C-banding.

Lampropholis caligula Ingram and Rawlinson. 2n=30 The standard karyotype can be distinguished from that of L. basilicus by the telocentric pair eight and by the largest microchromosome pair being metacentric (Fig. 2b). C-bands (not illustrated), were minimal and confined to the centromeres.

Lampropholis challengeri ( Boulenger). 2n=30 The karyotype differed from that of L. basiliscus by having an acrocentric pair nine (Fig. 2c). Centromeric C-bands were minimal but telomeric C-bands were present on all members of the complement (Fig. 5b).

Lampropholis czechurai Ingram and Rawlinson. 2n=30 In three male specimens from two localities, pair seven was heterozygous for a pericentric rearrangement (Fig. 2d). Apart from pair seven, this species differed from L. basiliscus in having an acrocentric pair nine. There were prominent centromeric C-bands in this species (Fig. 5c). The first four pairs had telomeric C-bands. C-bands on the heteromorphic seven pair were confined to the centromere and appeared tq be equal in intensity.

Fig. I . Standard karyotype of female Lampropholis basiliscus from Charpillan Ck.. Queensland (Qld) The bar indicates IOfim.

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226

Fig. 2. Partial standard karyotype of some Lampropholis. (a) male L. amicula from Mogill State Forest (S.F.) Qld.; - (b) female L. ca/&y/a from

Barrington Tops, New South Wales (N.S.W.): - (c) female L. challfngeri from Neutral Bay, N.S.W.; - (d) male L. czrchurai from Charmillan Ck.. Qld.; - (c) female L. Micara from Watagan S.F., N.S.W.; -(f) female L. guichenoti from Pymble, N.S.W.; - (g) female L. mirahilis from Cape Cleveland. Qld.; - (h) female L. mustrlina from Greenwich, N.S.W. The bar indicates IOpm.

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227

Fis. 3. PwM. ~.at&.rd k.aqW.ypevaf ~wcw Lampraphdi.. (3 c 2 m.ak L. c+, A ham. KurcW.k,QM..;- (b) A. few.dt L.. s+. B fvxv. bf.t.. &.P.% Fqplrp_,

Qld.; (c) male L. sp. C from Bulburin S.F.. Qld. Note the heteromorphic pair of microchromosomes; -(d) female L. sp. C from Crediton Ck.,

Qld. Note absence of heteromorphism amongst the microchromosomes; - (e) male L. sp. D from Mt. Nebo, Qld. The bar indicates IOpm.

Lampropholis delicata (De Vis). 2n=28

The taxonomic status of L. delicata has recently been stabilised by Mather (1990) with the nomination of a

neotype. However, the species still lacks a description adequate for identification purposes. Mather (1990)

also found three other electrophoretically distinct

forms which occur within the geographic range of L. delicata, which he named Forms B, C and D. These

forms had restricted ranges, all within Queensland.

Thus of the four forms which Mather (1990) identified, the specific expithet delicata is applied to the more

geographically widespread of these species (for ex- ample Cogger, 1983).

The standard karyotype differed from that of L. basiliscus in the diploid number and in that pair eight

was usually telocentric (Fig. 2e). The five pairs of microchromosomes were either telocentric or acro-

centric. In general, centromeric C-banding was mi-

nimal and telomeric C-bands were present on the

larger macrochromosomes and distally on pair nine (Fig. 5d).

Ten individuals from the central part of the species’ range were heterozygous for a variety of rearrange-

ments (Table 1). One specimen was heterozygous for a

Robertsonian rearrangement involving one of the two largest pairs of macrochromosomes (Fig. 4a). Two

individuals from different locations were heterozy-

gous for a pericentric rearrangement of pair six (Fig.

4b). Three specimens from two localities were hetero- zygous for a pericentric rearrangement of pair eight (Fig. 4c), while a fourth from a third locality was homozygous for the variant chromosome. In both of

the latter mentioned rearrangements C-bands were confined to the centromeres of these pairs.

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228

d5

6 7

6 7

6 7

4

8 9

8 9

Fig. 4. Partial karyotypes of Lampropholis delicata showing

structural heteromorphisms. (a) male from Watagan S.F., N.S.W. heterozygous for a Robertsonian rearrangement of one of the two

larger pairs of macrochromosomes; - (b) female from Connondale

Range. Qld. heterozygous for a pericentric rearrangement of pair six; - (c) male from near Nowra, N.S.W. heterozygous for a pericentric rearrangement of pair eight; -(d) female from Wianga-

rie S.F., N.S.W. with a short arm on one member of the usually

telocentric pair nine. C-banding (lower pairs eight and nine) demonstrates that the additoinal material is heterochromatic. The

bar indicates 10pm.

There were no apparent differences in bivalent morphology at first prophase of meiosis between the

homozygotes and heterozygotes for the pericentric rearrangement of pair eight. The seven largest bi-

valents routinely showed more than one chiasma, while the remaining bivalents each displayed a single

chiasma. In the absence of significant centromeric C-band markers it was not possible to determine if there was any chiasma localization in either the homomorphic or heteromorphic bivalents. All stages

of meiosis observed in the homozygotes were present in the heterozygotes. As both of the heterozygotes for the pericentric rearrangement of pair six were females, meiotic analysis was precluded.

A further four specimens were heterozygous for the addition of a small short arm on pair nine (Fig. 4d).

One of these was also heterozygous for additional material on one of the larger microchromosomes. C-

banding indicated that the additional material in both cases was totally heterochromatic.

Lampropholis guichenoti (Dumeril and Bibron). 2n=30

The standard karyotype of this species was distin- guishable from that of L. basifiscus by an acrocentric

pair seven and by the metacentric nature of pair nine

and the largest pair of microchromosomes (Fig. 2f).

This karyotype is generally similar to that reported by King (1973) for animals collected near Jenolan Caves, N.S.W.. Centromeric C-bands were prominent in this

species (Fig. 5e). Both specimens C-banded were

heterozygous for proximal C-bands on the fifth pair and the intensity of this band varied between in-

dividuals. Prominent ‘grey’ C-bands were seen ter- minally on the long arm of the second largest pair of

macrochromosomes. The seventh pair had a fine

distal C-band on the long arm.

Lampropholis micrabilis Ingram andRawlinson. 2n=30 The karyotype differed from that of L. basilicus by

having a telocentric pair eight and a submetacentric pair nine (Fig 2g). There was insufficient material for

C-banding.

Lampropholis mustelina (O’Shaughnessy). 2n=30 The karyotype of this species differed from that of L.

basiliscus by the largest pair of microchromosomes

being metacentric (Fig. 2h). Centromeric C-bands were minimal except for the largest pair of chromo-

some pair nine.

Lampropholis sp. A. 2n=30 The standard karyotype can be distinguished from

that of L. basiliscus by the telocentric pairs seven and

eight and the submetacentric pair nine (Fig. 3a). The specimen C-banded had prominent centromeric C- bands and fine proximal bands either side of the centromere on two pairs of the larger macrochro- mosomes (Fig. 6a). There were prominent proximal

C-bands on the telocentric pairs seven and eight.

Lampropholis sp. B. 2n=30 The standard karyotype differed from that of L. basiliscus in that the seventh and tenth pairs were

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229

Fig. 5. C-band karyotypes otsome Lampropholis. (a)female L. basiliscus from Charmillan Ck., Qld.; - (b) male L. challengerifrom Randwick, N.S.W.: - (c) male L. czechurui from Charmillan Ck., Qld.; -(d) male L. delicata from Bondi S.F., N.S.W.; - (e) female L. guichenoti from Pymble, N.S.W. Note the interstitial C-band on pair five; - (f) male L. musrelina from Wentworth Falls, N.S.W. The bar indicates 10pm.

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Fig. 6. C-band karyotypes ofsome Lampropholis. (a) male L. sp. A from Charmillan Ck, Qld.; - (b)a male L. sp. C from Crediton Ck, Qld. Note the heterochromatic nature of larger element of the heteromorphic microchromosome pair; - (c) a female L. sp. C from Crediton Ck, Qld. Note the absence of a heteromorphic microchromosome pair; - (d) male L. sp. D from Mt. Glorious, Qld. The bar indicates 10pm.

acrocentric while the eight was telocentric (Fig. 3b). There was insufficient material for C-banding.

Lampropholis sp. C. 2n=30 The standard karyotype can be distinguished from that of L. basiliscus by the telocentric pairs seven and eight and the submetacentric pair nine (Fig. 3c, d). Six male specimens from three widely separate localities in central and southern Queensland displayed hetero- morphism in one of the two smaller pairs of micro- chromosomes. C-banding revealed that the larger telocentric element was entirely heterochromatic, while the heterochromatin of its presumed partner was

confined to the centromere (Fig. 6b). This hetero- morphism was absent from the only female examined (Fig. 6c), suggesting that it may be a sex chromosome pair but more specimens must be sampled before this can be confirmed. There were prominent centromeric C-bands on pairs six, seven, eight and on three pairs of microchromosomes. Fine proximal C-bands appear- ed on either side of the centromere on the two largest pairs of macrochromosomes.

Lampropholis sp. D. 2n=28 The standard karyotype differed that of L. basiliscus by the possession of telocentric pairs seven and eight

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231

and a submetacentric pair nine (Fig. 3e). Centromeric C-bands were prominent on all pairs except the four

larger pairs of macrochromosomes. Three of the

largest pairs of macrochromosomes had fine proximal

C-bands either side of the centromere. There was a tine proximal C-band on the telocentric pair seven. A male specimen was heterozygous for the addition of a small

C-band to the distal end of a pair of microchromo- somes which also had a fine interstitial band on both

homologues (Fig. 6d).

Discussion

Karyotype evolution

Various types of karyotypic changes were observed in Lampropholis. Most karyotypic differences between

species can be accounted for by pericentric rearrange- ments. The most frequent types of karyotype re-

arrangement observed in vertebrates involve changes

in chromosome number due to fusion-fission events or changes in centromere position due to pericentric rearrangements. The former has certainly been the

predominant mode in geckos (King, 1983a) and

iguanids (German et al., 1967) while the latter is prevalent in varanids [King & King, 1975).

In two forms of Lampropholis, L. delicata and L. sp.

D the number of microchromosomes is reduced.

Reduction in the number of microchromosome pairs is commonly encountered in reptiles especially in the

iguanid genus Anolis (Gorman, 1973), some Gehyra (King, 1983a), chamaeleons and anguid lizards (Bick- ham, 1983). In some cases microchromosomes fuse

together to create new macrochromosomes or are

converted into macrochromosomes by addition of heterochromatin. Neither of these mechanisms has

operated in the case of Lampropholis. Instead in Lampropholis a microchromosome pair has been lost or translocated onto a larger macrochromosomal

pair. It is doubtful wether G-banding would help

decide between these two possibilities because of the small size of the element involved.

Heterochromatin has not played a major role in karyotypic differentiation between species oflampro- pholis being rather minimal in content and confined mainly to centromeric and telomeric areas. Where

additional heterochromatic blocks were observed, they occurred uniquely or as wide spread polymor-

phisms providing a further source of intraspecific

karyotypic variation. A further form of karyotype variation which ap-

pears widely but infrequently in lizards is the occurr- ence of heteromorphic sex chromosomes (reviewed in King, 1977). In L. czechurai and L. sp. C. the

observation of males from more than one locality with

a heteromorphic chromosome pair suggests that sex chromosomes have differentiated morphologically in

these forms. However, in the absence of adequate data for females this interpretation remains speculative

although highly suggestive. In support, the male is the

heterogametic sex in other skinks where hetero- morphic sex chromosomes occur (Wright, 1973; Har- dy, 1979). The involvement of two different chromo-

some pairs indicates two independent origins for morphologically differentiated sex chromosomes in

Lampropholis. The occurrence of heteromorphic sex

chromosomes in lygosomine skinks will be addressed more fully in a forthcoming paper.

Karyotypic variation in Lampropholis delicata

Various structural rearrangements contribute to the karyotypic variation observed in some populations of

L. delicata. The presence of individuals with unique rearrangements i.e. a Robertsonian rearrangement

involving a macrochromosome pair, suggests that

these are rare mutants rather than chromosomal polymorphisms. As sample sizes at most localities are

small there must be uncertainty about the frequency of such rearrangements. The wide spread geographic

distributions of the telocentric form of chromosome pairs six and eight are indicative of pericentric re-

arrangement polymorphisms. Where sufficient num- bers of individuals have been studied structural hete-

rozygosity has been observed in species from a number of lizard families (King, 1983a), but there is no

evidence for meiotic problems in individuals hetero- zygous for these types of rearrangements in lizards (King, 1983a; Porter & Sites, 1985).

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232

Systematic implications

The most significant taxonomic implication of the

chromosome variation in Lampropholis, is the status of the four distinct chromosome forms (L.sp. A-D)

found among populations of L. delicata group ani-

mals. Three of these taxa had previously been found to be distinct on biochemical and morphological grounds

(Mather, 1990). Thus forms B, C and D of Mather (1990) are equivalent to L. sp. C, D and A respectively.

It should be appreciated that each unique karyo-

morph may not constitute a new species as the postulated chromosome rearrangements which dis- tinguish these karyomorphs may not constitute a

significant barrier to gene flow (Lande, 1979), although this remains untested in the present case. However,

numerous examples of chromosome races being even- tually recognised as species exist (e.g. King, 1982,

1983b; Storr, 1979).

L. delicata and L. sp. C appear to be distinct biological species. At Granite Ck., where two indi-

viduals of each karyomorph were collected in sym- patry, differences in morphology of pair 7 and in

diploid number were maintained as well as the presence of probably heteromorphic sex chromo-

somes in L. sp. C only. The null hypothesis under test is that the four individuals from this locality were

sampled at random from a single population which is therefore in Hardy-Weinberg equilibrium. The esti-

mated frequenceis of the submetacentric and telo- centric forms of pair seven are p=OS and q=OS.

Likewise the estimated frequencies of the two diploid

numbers is p=O.5 and q=O.5. The expected propor- tion of heterozygotes for either of these two characters is 2pq=O.5. The probability of not observing an

individual heterozygous for the rearrangement in pair

7 and/or with 29 chromosomes is [l-(2X0.5X0.5)]4‘*2 = 0.39% (Richardson et al., 1986). Thus a null hypothesis that the sample of four individuals was

drawn from a single random breeding population is not supported. An alternative hypothesis that the karyomorphs represent distinct biological species is also supported by the presence of fixed allelic differ-

ences at 20% of their loci (Mather, 1990). No further cases of sympatry occurred in the

samples of L. sp. A, B, C, D and L. delicata group

species studied here. Ultimately, a taxonomic decision

of the status of the four karyomorphs will depend on an integration of ecological and morphological data so that comparison with the appropriate species can be

made. Conversely karyotypic uniformity was observed in

three species (L. delicata, L. challenger-i, L. mustelina) in which taxonomic problems exist on morphological

grounds (G. Ingram, pers. comm.). For instance, L. delicata is a widely distributed species showing varia-

tion in body size, tail length, colouration and the

extent of sexual dichromatism. In this study, karyo- types of animals from 25 localities, covering a major part of the range, showed overall uniformity. Karyo-

types of specimens from the far north of the range around the Atherton Tableland remain to be ex-

amined. Taxonomic investigations of L. delicata, L.

challengeri and L. mustelina should be tackled further by a biochemical technique such as allozyme electro-

phoresis which could establish a genetic framework for the resolution of the taxonomic status of morpho-

logical variants. Phylogenetic interpretations based on these data

must await more information. Too little is known of the karyotypes of appropriate outgroup genera of

lygosomine skinks to test the monophyly and the intergeneric relationships of Lampropholis.

Acknowledgements

This study was made possible by the following people

who generously provided specimens: S. Burgin, H. Cogger, J. Covacevich, H. Ehmann, R. Green, A. Greer, M. Hutchinson, G. Johnston, M. Mahony, P.

Mather, R. Sadlier, and G. Webb. The fauna authori- ties of the States concerned are thanked for their

cooperation. S. Burgin, H. Ehmann, A. Greer, G. Ingram, and P. Mather generously shared their un-

published information. P. Baverstock, R. Close, A. Greer, P. Johnston, and G. Sharman reviewed the manuscript. Field work for this study was supported in part by an Australian Museum Postgraduate

Award.

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Appendix 1

Specimens of Lampropholis examined. N: number of specimens examined. Registration Number Prefixes: AMS R: Australian Museum, Sydney: QM J: Queensland Mu-

seum. Brisbane; SAMA R: South Australian Museum, Adelaide: HE: Harry Ehman collection; SB: Shelly Burgin collection; L:

Stephen Donnellan collection.

L. amicuh (2): Mogill S.F., Qld., 27”39’S., 150”52’E.. AMS

RI 11479. Rainbow Beach, Qld.. 25”55’S., 153”06’E., RI 11790. L. basihws (2): Charmillan Ck., Qld., 17”43’S., 145”3l’E., AMS

RI 1401 I-12. L. caligulu (I): Barrington Tops, N.S.W., 32”O?‘S., 151”28’E.. AMS RI 15279. L. challengeri (I 1): Randwick, N.S.W.. 33”55’S.. 151”15’E., LACHAl6-17. NeutralBay,N.S.W.,33”51’S.,

151”12’E., SB219. Bellevue Hill, N.S.W.. 33”5l’S., 151”15’E., LACHA22-23. near Brinerville. N.S.W.. 30”28’S.. 152”33’E., AMS

Rlll739.Mt. Warning.N.S.W..29°18’S.,153”16’E.,AMSR97821. Alstonville, N.S.W., 28’5O’S., 153’26’E.. HE2569, 2572. Mt.

Glorious. Qld., 27”2O’S., 152”45’E.. AMS R97818, SB362. L. czechurui (3): Charmillan Ck., Qld., 17”43’S., 145”3l’E.. AMS

RI l4009-010. Millaa Millaa,Qld.. 17031’S.. 145”37’E., QM 341356. L. c/ci;catu (50): Launceston,Tasmania, 41”27’S., 147”lO’E.. AMS

RI 15281-4. Marble Range, S.A., 34”26’S., 135”29’E., SAMA R297X5. near Port Lincoln, S.A., 34”42’S., 135”49’E., SAMA

R29786-7. 25km N. Avenue, S.A., 36”45’S, 140”1‘3’E, SAMA R35818-9. Eltham, Victoria, 37”43‘S., 145”09’E.. AMS RI 15278,

I 11609.. Bondi S.F., N.S.W., 37”08’S., 149”09’E., AMS RI 12353. near Nowrd. N.S.W.. 35’03’S.. 150”20’E., AMS Rl02759-61.

Coogce, N.S.W., 33”55’S., 151”15’E., AMS R104796. Pymble, N.S.W., 33”45’S.. 151”08’E., LADEL61, SB65. one specimen lost.

Neutral Bay, N.S.W., 33”5l’S., 151”12’E., LADEL62. Watagan SF., N.S.W.. 33”15’S., 151°20’E.. AMS R97827, 10478789,

LADEL27. Doyalson. N.S.W.. 33”13’S., 151”30’E., AMSR104203. Myall Lakes, N.S.W., 32”25’S., 152”30’E., LADEL7, 15. Werri-

kimbe N.P.. N.S.W., 31”09’S.. 152’14’E., AMS RI1 1470. Carrai S.F..N.S.W.. 3l”Ol’S.. 152”20’E.,AMSR112322. near Brinerville,

N.S.W., 30”28’S., 152”33’E., AMS R102763, 111787. Cambridge Plateau, N.S.W., 28”45’S., 152”45’E., AMS RII 1839. Wiangarie

SF., N.S.W., 29”08’S., 152”07’E.. AMS RI 11472, 785-6, 474, 115298. Scarborough, Qld., 27”12’S., 153”07’E., AMS Rl11837,

478, 480. Connondale Range, Qld., 26”33’S.. 152”35’E.. AMS Rl04196. Bunya Mtns.. Qld.,26”55’S., 151’37’E.. AMS Rll4097- 8. Granite Ck., Qld., 24”36’S., I5 1”4O’E., 545295-6. Rockhampton.

Qld., 23”22’S., 150”32’E.. AMS RI 11833. Byfield, Qld.. 22”5l’S.. 150”39’E., HE2373. Mt. Morgan, Qld.. 21”28’S., 150”22’E., AMS RI 15268-9. L. ,pichenoti (4): near Glare, S.A., 33”5O’S., 138”37’E., HE3334. Pymble, N.S.W., 33”45’S., 151°08’E., AMS Rl11574-5. SB64. 1.. mirabilis (I): Cape Cleveland, Qld., 19”l I’S, 147°01’E..

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AMS Rll1828. L. mustelina (4): Greenwich, N.S.W., 33”5O’S., 17’24’S., 145”49’E., QM J4@333,40036-9. L. sp. C (8): Connondale

151”l l’E., AMS R96788. Bellevue Hill, N.S.W., 33”53’S., Range. Qld.. 26’33’S., 152”35’E., AMS Rl02778-9. Granite Ck.,

151”15’E., SB220. Wentworth Falls, N.S.W., 33O43’S., 150”22’E., Qld., 24”36’S., 151”40’E., QM 545297-8. Bulburin S.F., Qld., AMS R111784. near Barry, N.S.W., 31”35’S., 151”25’E., AMS 24”3O’S., 151”30’E., HE2373. Crediton Ck., Qld., 21”12’S.,

R102748. L. sp. A (6): Kuranda, Qld., 16”49’S., 145”38’E., QM 148”32’E., AMS R111825,829-30,834. L. sp. D (5): Mt. Glorious,

541360. Charmillan Ck., Qld., 17”43’S., 145”31’E., QM 541361-2, Qld., 27”2O’S., 152”45’E., AMS R111835,37. Mt. Nebo, Qld.,

AMS R94537, 538, 94545. L. sp. B (4): Mt. Bartle Frere, Qld., 27”24’S., 152”45’E., AMS R97875,77.