Download - REVIEW OF LITERATURE - Shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/13745/8/08_chapter 2.pdf · REVIEW OF LITERATURE 15 REVIEW OF LITERATURE The Heteroptera is a numerically

REVIEW OF LITERATURE

15


The Heteroptera is a numerically large and highly diverse group of insects.

About 42,300 species belonging to 89 families from this suborder have been described

many of which are pests of economically important food plants (Henry, 2009).

Heteroptera comprises eight major infra-orders namely Coleorrhyncha,

Enlcocephalomorpha, Dipsocoromorpha, Leptopodomorpha, Gerromorpha, Nepomorpha,

Cimicomorpha and Pentatomomorpha. Within Cimicomorpha, Reduviidae and Miridae

are the major families. Reduviidae is one of the largest families of terrestrial Heteroptera,

globally comprising 6601 species and subspecies in 961 genera and 25 subfamilies

(Maldonado, 1990). These insects are abundant, occur worldwide and are voracious

predators, thus are named assassin bugs (Ambrose, 1999; Schaefer and Panizzi, 2000).

Assassin bugs may not be useful as predators of specific pests as they are polyphagous

but they are valuable predators in situations where a variety of insect pests occur. They

kill more prey than they need to satiate themselves by their behavior of indiscriminate

killing. Their importance as predators and their conservation augmention for utilization in

biocontrol programmes has been discussed by Ambrose (1987, 1999).

(A) Chromosome complement and meiosis :

(a) Heteroptera:

The pioneer contribution towards the cytological aspects of this suborder was made

by Henking (1891) which was followed by very elaborate cytological investigations by

Montgomery (1898), McClung (1901) and Wilson (1909 a, b & c). The chromosomes of

Heteroptera are holocentric and the occurrence of the diffuse centromere was proposed

and evidenced in a series of publications by Schrader (1935, 1940 a & b, 1947). Schrader


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(1935) observed chromosomes of Protenor belfragei (Alydidae) to be without a discrete

localized centromere. Rather spindle fibers were found to be attached all over the surface

of the chromosome. Further, he observed that the chromosomes showed no bending at

anaphase-I and two halves remained parallel to one another as they passed on to two

poles. The hypothesis of diffuse kinetochore was extended to the entire group of

Heteroptera by Schrader (1940 a & b, 1947). He elucidated the importance of diffuse

centromere in the evolution of this group. He interpreted that the fragments formed as a

result of accidental breakage of chromosome with diffuse kinetochore remained

functional and behaved normally at mitosis and passed through several generations

thereby changing the fundamental number of a species. Based on chromosome behavior

during mitosis as well as meiosis, Troedsson (1944), too, claimed that the heteropteran

chromosomes were holocentric. Hughes-Schrader (1948) examined the behavior of

heteropteran chromosomes during mitosis and recorded that:

1. Each chromosome orientated with its long axis at right angle to the polar axis at

mitotic metaphase.

2. No primary constriction appeared during mitosis.

3. Terminalisation of chiasmata was completed by late diakinesis.

4. Chromosomal fibers were organized along the entire length of each chromatid so

that mitotic chromatids separate by parallel disjunction.

These features were further supported by Heizer (1950, 1951), Halkka (1956) and

Lewis and Scudder (1957). Additionally, holocentricity was demonstrated experimentally

in the Heteroptera by Hughes-Schrader and Ris (1941) and Ris (1942) also. However,

Mendes (1949), Parshad (1957 a, b, c & d) and Rao (1958) suggested the heteropteran


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chromosomes to be monocentric because of the presence of a presumed primary

constriction at mitotic metaphase. This claim was strongly criticized by Hughes-Schrader

and Schrader (1961). Piza (1958), on the other hand, suggested that the heteropteran

chromosome was dicentric. Most of the authors, however, supported the opinion of

holocentric nature of chromosomes (Manna, 1951; Banerjee, 1959; Wolfe and John,

1965; Ueshima, 1966, 1979; Ueshima and Ashlock, 1980). La chance et al. (1970) further

elaborated that even in holocentric chromosomes, some fragments particularly small

ones, may be eliminated or delayed in the anaphase separation. At the ultrastuctural level,

Buck (1967) while working on Rhodnius prolixus, observed an extensive layer of

material all over the mitotic chromosome to which spindle fibers were attached. Meiotic

chromosomes, on the other hand, did not show this structure. Comings and Okada (1972)

carried out investigations on formation of kinetochore plates in Heteroptera with a diffuse

kinetochore during mitosis and meiosis, and discussed their suppression during

terminalization of chiasmata. They observed a centromere plate extending for upto 75%

of the length of the mitotic chromosome in Oncopeltus fasciatus but centromeric plate

was absent in meiotic chromosomes. It was interesting that repeat DNA sequences were

short and scattered over the chromosome. On the other hand, in organisms with

monocentric chromosomes, repeated DNA sequences are in high concentration near the

centromere (Lagowsky et al., 1973). Ruthman and Permantier (1973) found the

centromere to cover only 4.2% of the entire chromosome in Dysdercus intermedius.

White (1973) elaborated that the ability of spindle fibres to attach large part of the

chromosome during cell division becomes the basis for the principle of Karyotypic


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Orthoselection. The aberrations induced by radiations and chemicals help to understand

various aspects of the chromosomes, its organization, rearrangements and evolution.

The behavior of holokinetic chromosomes during the course of mitosis and meiosis

has been studied by Darlington and Upcott (1938) by taking the measurements of packing

and contraction in the chromosomes. Darlington (1939) further discussed the genetic and

mechanical properties of sex chromosomes during division in Heteroptera. The details of

kinetic activities of autosomes and sex chromosomes during meiosis have been discussed

by Hughes-Schrader and Schrader (1956, 1957, 1961), Gonzalez-Garcia et al. (1996) and

Perez et al. (1997, 2000).

Any scientific study of an organism needs its prior identification, naming and

classification. Taxonomists use various morphological characters to bring different

members of a group of plants and animals under a systematic list showing their natural

phylogenetic relationships. With the growing knowledge of nuclear structures, the

cytologists believe that chromosomal attributes are also morphological and can be

substantially utilized for the purpose of taxonomy in addition to general morphological

features. In Heteroptera, karyotype is prone to evolutionary changes either by fusions or

fragmentations of chromosomes which lead to decrease or increase in the chromosome

number in different species. Every fusion and fragmentation appears first in a

polymorphic state prior to its fixation in the karyotype. The importance of heteropteran

material for cytological studies from evolutionary point of view was recognized in the

beginning of twentieth century by Montgomery (1901a & b, 1904, 1906), Wilson (1905a,

b & c, 1906, 1907a, b & c, 1909a & b, 1910, 1911, 1912, 1913, 1932) and Browne (1916)

who carried out cytological investigations along with morphological characters of


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Heteroptera. Payne (1909, 1910, 1912), Chickering (1927a & b, 1932, 1933) and

Nishimura (1927) stressed upon the importance of chromosome studies of different

families of Heteroptera with respect to their karyotypic evolution. This practice is

becoming more and more obvious in modern systematics. Cytologists are interested in

collecting the cytological data of more and more species of Heteroptera. At international

level, karyological studies on Heteroptera have been done by Foot and Strobell (1907,

1912, 1914), Schrader (1932, 1935, 1939, 1940a & b, 1941a & b, 1945a & b, 1946a & b,

1947, 1960a & b), Toshioka (1933, 1934, 1935, 1936, 1937), Geitler (1937, 1938, 1939a

& b), Pfaler-Collander (1937, 1941), Freeman (1940), Mc Clung (1940), Hughes-

Schrader (1931, 1940, 1942, 1948, 1955), Schrader and Hughes-Schrader (1956, 1958),

Ekblom (1941), Troedsson (1944), Yosida (1944, 1946, 1947, 1950, 1956), Xavier

(1945), White (1948), Heizer (1950), Lewis and Scudder (1957), Leston (1957, 1958),

Ueshima (1963, 1966, 1979), Mikolajski (1964, 1965, 1967a & b, 1968, 1970,1971),

Takenouchi and Muramoto (1964, 1967, 1968, 1969, 1970a & b, 1971a & b, 1972a & b,

1973), Muramoto (1973a, b, c & d, 1974, 1975a, b & c, 1976, 1977, 1978a & b, 1979,

1981, 1982, 1985), Akingohungbe (1974), Kuznetsova and Petropavlovskaya (1976) and

Reddi and Chari (1976, 1978).

Extensive cytological studies have been carried out on Heteroptera by Ueshima

and Ashlock (1980), Sands (1982a & b), Nuamah (1982), Newman and Cheng (1983),

Nokkala and Nokkala (1983, 1984, 1997, 1999, 2004), Papeschi and Bidau (1985),

Nokkala (1985, 1986). Papeschi (1988, 1991, 1992, 1994, 1995, 1996), Papeschi and

Mola (1990 a & b), Grozeva and Kuznetsova (1990, 1993), Panzera et al. (1992, 1995,

1996, 1997, 1998, 2000), Perez et al. (1992, 1997, 2000, 2004, 2005), Grozeva (1995a &


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b, 1997), Nokkala and Grozeva (1997), Bressa et al. (1998, 1999, 2001a & b, 2002, 2003,

2005, 2008), Rebagliati et al. (1998, 2001, 2002, 2003, 2005, 2010 a & b), Tartarotti and

Azeredo-Oliveira (1999a & b), Jacobs and Liebenberg (2001), Grozeva and Nokkala

(2002), Jacobs and Groenveld (2002), Papeschi and Bressa (2002, 2004, 2006), Papeschi

et al. (2003), Severi-Aguiar and Azeredo-Oliveira (2003, 2005), Nokkala et al. (2003,

2006 a & b), Jacobs (2004), Grasiela et al. (2004), Ituarte and Papeschi (2004), Kerzhner

et al. (2004), Franko (2005), Grozeva et al. (2005, 2006, 2007, 2008, 2009), Franko et al.

(2006), Bressa and Papeschi (2007), Poggio et al. (2007), Souza et al. (2007a, b & c,

2008 a & b, 2009, 2010), Bardella et al. (2008), Kuznetsova and Grozeva (2008), Pires

(2008), Toscani et al. (2008), Zhang and Zheng (1999), Kaur and Semahagn (2010 a)

and Yang et al. (2012).

In India, major contribution to the cytology of Heteroptera has been made by

Manna (1950, 1951, 1957, 1958, 1962, 1982, 1983, 1984) describing the chromosome

complements of several Indian species of different families of Heteroptera and discussing

cytoevolutionary trends. The course of meiosis and chromosomal behaviour in various

heteropterans species belonging to different families have been discussed by Das Gupta

(1950), Ray Chaudhuri and Manna (1952, 1956), Bawa (1953), Rao (1954, 1955, 1958),

Dutt (1955, 1957), Sharma and Parshad (1955a & b, 1956), Das (1956, 1958), Parshad

(1956, 1957a, b, c & d, 1958), Sharma et al. (1957), Srivastava (1957, 1965), Banerjee

(1958, 1959), Bagga (1959), Ray Chaudhuri and Banerjee (1959) and Jande (1959 a, b &

c, 1960 a, b & c). Manna (1962, 1982, 1983, 1984), Rajasekharasetty (1963),

Bhattacharya and Halder (1978), Malipatil (1979), Manna and Deb-Mallick (1980, 1981a

& b, 1982, 1983, 1984), Barik et al. (1981), Manna and Dey (1981), Mittal and Joseph


21

(1981, 1982, 1984), Manna et al. (1985), Dey and Wangdi (1985, 1988, 1990), Satapathy

and Patnaik (1988, 1989, 1991), Satapathy et al. (1990), Kaur et al. (2006, 2009), Kaur

and Suman (2009), Kaur and Singh (2010) and Kaur and Semahagn (2010 b) made a

significant contribution towards meiotic studies in Heteroptera.

Heteroptera is characterized by sex determination mechanisms of simple

(XY/XX, XO/XX), multiple (XnO/XnXn, XnY/XnXn and XnYn/XX) and neo-XY types

(Chickering and Bacorn, 1933; Schrader, 1940a & b; Manna, 1951, 1984; Jande, 1959b

& c; Ueshima, 1979; Nokkala and Nokkala, 1983; Nokkala et al., 2003). Different views

have been proposed about the origin and evolution of sex determining systems in

Heteroptera. Ueshima (1979) considered XO system encountered commonly in primitive

heteropteran taxa to be the ancestral one and XY to be derived from it. It was further

suggested that multiple sex chromosome systems of Heteroptera evolved from the XY

system. By contrast, Nokkala and Nokkala (1983, 1984) considered XY system to be the

ancestral one and dominant sex mechanism and XO system to be derived from it. In

Heteroptera, multiple sex mechanisms are not accompanied by any reduction in autosome

number implying their origin by fragmentation of sex chromosomes. Evolution of

multiple sex determination mechanisms have been discussed by Payne (1909), Troedsson

(1944), Ueshima (1979), Barik et al. (1981), Manna (1982, 1984), Grozeva and Nokkala

(1996) and Bressa et al. (1999). Neo-XY sex determination system is thought to be

originated as a result of autosome-sex chromosome fusion. Involvement of autosomes in

sex mechanisms has been discussed by Chickering and Bacorn (1933), Schrader (1940a

& b), Jande (1959b & c), Ueshima (1979), Bressa et al. (1999, 2009), Nokkala and


22

Nokkala (1999), Jacobs (2003, 2004), Papeschi and Bressa (2006) and Poggio et al.

(2007).

In groups with holocentric chromosomes, meiosis is post-reductional i.e.

chromosomes divide equationally during first meiotic division and reductionally during

the second meiotic division. This is true of Odonata, Trichoptera and Lepidoptera.

Heteropterans are unique in showing pre-reductional meiosis for autosomes and post-

reductional for the sex chromosomes. In Heteroptera, chiasma frequency is low. Single

chiasma per bivalent is the predominant condition. Sex chromosomes remain

achiasmatic. The general course of meiosis, behavior of different types of chromosomes

(autosomes, m-chromosomes, sex chromosomes) during meiosis and chiasma frequency

have been described and discussed by Das Gupta (1950), Ray Chaudhuri and Manna

(1952, 1955), Battaglia and Boyes (1955), Dutt (1955, 1957), Manna (1962, 1982, 1983,

1984), Takenouchi and Muramoto (1964, 1967, 1968, 1970a & b, 1971a & b, 1972a &

b), Ueshima (1966, 1979), Muramoto (1973a, b, c & d, 1974, 1975a, b & c, 1978 b,

1979), Camacho et al. (1985), Mola and Papeschi (1993), Bressa et al. (1998, 2001a &

b), Jacobs and Liebenberg (2001), Rebagliati et al. (2001, 2003), Jacobs and Groeneveld

(2002), Bressa et al. (2002), Papeschi et al. (2003), Poggio et al. (2007, 2011) and Kaur

et al. (2010).

Heteroptera is characterized by the presence of a pair of minute elements in some

families. The term m-chromosomes was first assigned by Wilson (1905 b) to a pair of

very small chromosomes in Coreid bugs which differed in meiotic behavior from both

autosomes and sex chromosomes. They remained unpaired or achiasmatic during meiotic

prophase and associated terminally to form a pseudobivalent at metaphase-I to ensure


23

regular segregation. Wilson (1905b) termed this pairing near metaphase-I to as touch

and go process. It is the behavior and not size that is critical in defining m-chromosomes

as in some cases they are of same size as conventional autosomes (Wilson 1911). The

touch and go process of m-chromosomes has been discussed in detail by Pfaler-

Collander (1941), Parshad (1957a, b, & d), White (1973), Roos (1976), Ueshima (1979),

Manna (1984), Nokkala (1986), Papeschi and Mola (1990 a & b), Gonzalez-Garcia et al.

(1996), Grozeva and Nokkala (1996), Suja et al. (2000), Nokkala et al. (2004) and

Castanhole et al. (2008). The tiny m-chromosomes claimed to be genetically inert

because of their heterochromatic nature, still occupy a vital position on the meiotic

metaphase spindle. They generally show allelocycly with respect to autosomes and sex

chromosomes during male meiosis but the heterochromatin characterization in this

chromosome pair showed that they are by no means completely heterochromatic. The

different pycnotic cycle of the m-chromosomes reflects differences in chromatin

packaging, and this pattern of chromatin condensation is probably related to the

regulation of gene expression (Bressa et al., 2005). However, there is still no information

on the genetic content of the m-chromosomes.

(b) Reduviidae :

Reduviidae is characterized by a modal diploid autosome number of 20 with a

range between 10 to 34 and both simple and multiple sex chromosome systems (XY/XX,

X0/XX and XnY/XnXn; male/female) (Ueshima,1979; Poggio et al., 2007). Cytogenetic

data is currently available for about 153 species belonging to 11 subfamilies; 79 of them

belong to Triatominae, 33 to Harpactorinae, 10 to Stenopodainae, 11 to Peiratinae, 9 to

Reduviinae, 3 to Ectrychodiinae, 3 to Emesinae, 2 to Phymatinae and 1 each to


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Bactrodinae, Hammacerinae and Saicinae (Poggio et al., 2007; 2011, Panzera et al.,

2010). The karyological studies on Reduviidae were initiated by Montgomery (1901 a &

b, 1906) followed by works of Payne (1909, 1910, 1912), Goldsmith (1916), Toshioka

(1933, 1936), Troedsson (1944), Yosida (1947), Schreiber and Pellegrino (1949), Barth

(1956), Makino (1956), Piza (1957), Ueshima (1966, 1979), Muramoto (1978 a), Panzera

et al. (1992, 1995, 1996, 1997, 1998, 2010), Perez et al. (1992, 1997, 2000, 2004, 2005),

Severi-Aguiar et al. (2006), Morielle-Souza and Azeredo-Oliveira (2007), De Rosas et al.

(2007), Poggio et al. (2007, 2011), Bardella et al. (2008), Costa et al. (2008) and Panzera

(2008). Reduviidae together with Cimicidae are the two heteropteran families in which

multiple sex chromosome systems of XnY have reached their broadest distribution and

variation. Origin and evolution of multiple sex mechanisms have been discussed by

Troedsson (1944), Ueshima (1966), Panzera et al. (1998) and Poggio et al. (2007).

In India, major cytogenetic works on the family Reduviidae have been done by

Manna (1950, 1951, 1962, 1984), Banerjee (1958), Jande (1959a & b, 1960b), Manna

and Deb Mallick (1981a), Dey and Wangdi (1988), Satapathy and Patnaik (1989),

Satapathy et al. (1990) and Kaur et al. (2009).

(B) Constitutive Heterochromatin

The word heterochromatin was coined by Heitz (1928) on the basis of a series of

cytogenetic observations. The link between visible heterochromatin structures in the

nucleus and the heritable gene silencing made it a major focus of study ever since the

stained cells from several species of moss showed a type of chromatin in the nucleus that

remained condensed throughout the cell cycle. The division of chromatin into

euchromatin and heterochromatin provided the first indication that chromatin


25

organization could influence gene function. There are abundant and increasing evidences

that C-heterochromatin contains genes and other functional DNA sequences which play

an important functional role in pairing and segregation of chromosomes and show

position effect variegation. The acquisition and accumulation of heterochromatin in the

karyotype of different species are well regulated by certain factors (Sumner, 2003).

The technique to locate C-bands was developed by Sumner (1971) for

distinguishing different human chromosomes. Later on, Seabright (1971) introduced

certain modifications to improve the results. Earlier attempts to apply banding technique

to invertebrate chromosomes were not very fruitful and encouraging as interpretation was

difficult owing to poor results obtained. More recently, different protocols for C-banding

have been suggested by Fernandez et al. (2002).

Constitutive heterochromatin is generally located as blocks of repetitive DNA

which are found to be organized in different patterns in insect genomes. They occur

either as families of repeat elements interspersed throughout the genome or as large

arrays usually representing satellite DNA sequences. The knowledge of organization of

repeated sequences in insects comes mainly from extensive studies on Drosophila and

other dipteran organisms by Brutlag (1980) and Blanchelot (1991).

C-banding has been a very useful tool in the detailed analysis of chiasma

terminalisation, heterochromatin polymorphism and population variations in insects as

indicated by works carried out on Orthoptera. Shaw (1971) carried out C-banding on

three species of genus Stethophyma which showed heterochromatin polymorphism with

respect to both autosomes and supernumerary chromosomes. In a similar study, Camacho

et al. (1981) reported C-heterochromatin variations in different species of genus


26

Eumigus. Fox et al. (1973) and Santos and Giraldez (1978) analysed the effect of C-

heterochromatin on chiasma terminalisation in Schistocerca gregaria and Chorthippus

biguttulus respectively. Shaw (1976) and Shaw et al. (1976) discussed the structural

differentiation of chromosomes with respect to the distribution of constitutive

heterochromatin during divergence of races of Caledia captiva. John and King (1977a &

b, 1980) studied heterochromatin variations in the patterns of C-banding in different

populations of Cryptobothrus chrysophorus. Gonsalvez and Fernandez (1981) applied C-

banding technique on natural population of Gomphocerus sibiricus. Santos and Giraldez

(1982) and Santos et al. (1983) detected qualitative variations in C-heterochromatin in

some other Orthopterans.

Muramoto (1985) applied differential Giemsa staining technique to other insect

orders such as Coleoptera, Dermaptera, Hemiptera, Lepidoptera along with Orthoptera

and confirmed the presence of definite centromeres in Coleoptera and Orthoptera and

diffuse centromere in Dermaptera, Lepidoptera and Heteroptera.

Initial attempts to identify and characterize individual chromosomes of

heteropteran species by using C-banding failed to yield satisfactory results because of

holocentric nature of chromosomes. But with improved methodology, C-banding was

successfully employed to species belonging to Reduviidae, Pentatomidae, Coreidae and

Lygaeidae by Maudlin (1974), Muramoto (1975a, 1976, 1978a, 1980, 1985), Solari

(1979), Camacho et al. (1985) and Kaur et al. (2010).

Dey and Wangdi (1990) described the C-banding pattern in Petillia patullicollis,

Ochrochira granulipes, Anoplocnemis phasiana (Coreidae), Leptocorisa acuta

(Alydidae), Iphita limbata (Largidae) and Nezara icterica (Pentatomidae) in an attempt to


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differentiate the basic karyotype of each species on the basis of banding pattern. Panzera

et al. (1992, 2000) and Perez et al. (1997, 2000, 2005) used C-banding to study

chromosomal polymorphism, its evolutionary importance and epidemiological relevance

in Triatoma infestans which is an important and the most widespread vector of

Trypanosoma cruzi, the causative agent of Chagas disease in human population. Grozeva

and Nokkala (2001, 2003) performed C-banding technique on thirteen species of lace

bugs (Tingidae) while Ituarte and Papeschi (2004) applied C-banding in Tenagobia

fuscata (Micronectidae). Perez et al. (2004) discussed the meiotic segregation and genetic

consequences of translocations in holocentric chromosomes and their role in evolution in

Mepraia gajardoi (Reduviidae) by applying C-banding technique. Bressa et al. (2005)

carried out a comparative study of C-banding pattern in species of Coreidae, Rhopalidae

and Largidae. Similarly, Grozeva et al. (2006), Kuznetsova et al. (2007), Palacio et al.

(2008) and Bressa et al. (2008) described heterochromatin heteromorphism in

Macrolophus costalis (Miridae), Arachnocoris trinitatus (Nabidae), Rhodnius pallescens

(Reduviidae) and Holhymenia rubiginosa (Coreidae) respectively.

Congeneric species can be differentiated from one another on the basis of

characteristic banding patterns of autosomes and sex chromosomes. Papeschi (1988,

1991, 1995) differentiated six species of Belostoma (Belostomatidae) viz., Belostoma

elegans, Belostoma micantulum, Belostoma oxyurum, Belostoma bifoveolatum,

Belostoma martini and Belostoma dentatum having same diploid number

(2n=26+X1X2Y), on the basis of C-banding patterns. Angus et al. (2004) compared C-

banded karyotypes of four British species of Notonecta (Notonectidae), Notonecta

glauca, Notonecta obliqua, Notonecta maculata and Notonecta viridis having the same


28

diploid complement. Similarly, Grozeva et al. (2004) revealed differences in C-banding

pattern in two species of Nabis (Nabidae). Waller and Angus (2005) used differential

staining methods to study five species of Corixa (Corixidae), Corixa punctata, Corixa

panzeri, Corixa iberica, Corixa dentipes and Corixa affinis having same diploid number

(2n=22+XY). Lanzone and Souza (2006 b) compared C-banding pattern of three species

of Antiteuchus (Pentatomidae), Antiteuchus mixtus, Antiteuchus sepulcralis and

Antiteuchus macraspis with 2n=14+XY. Angus et al. (2008) analyzed the C-banded

karyotypes of four species of Notonecta (Notonectidae). Similarly, Kaur et al. (2010)

differentiated three species of Dieuches (Lygaeidae), Dieuches uniguttatus, Dieuches

insignis and Dieuches coloratus on the basis of C- banding pattern.

(C) Sequence-specificity of C-heterochromatin:

Mechanism of chromosome banding with fluorochromes originated from a

comparative cytological approach in which a number of DNA binding compounds were

tested to search for A-T and G-C specific DNA ligands which could form fluorescent

complexes with base specific DNA. Two fluorescent stains, Quinacrine (Q) and 33258

Hoechst (H) were found to be specific for A-T rich regions in chromosomal DNA

(Weisblum and De Haseth, 1972, 1973; Weisblum and Haenssler, 1974). However, these

fluorochromes failed to give qualitatively identical staining with certain types of

heterochromatin (Hilwig and Gropp, 1972). Qualitative results were given by fluorescent

dye 4'-6-Diamidino-2-Phenylindole (DAPI) (Schweizer and Nagl, 1976). Then a search

was started for ligands which could form fluorescent complexes with G-C specific DNA.

Some DNA complexing antibiotics were examined. Finally, success was achieved with

Chromomycin A3 (CMA3) and Mithramycin (MM). Chromomycin and Mithramycin


29

form stable complexes with helical DNA with specificity for guanine (Ward et al., 1965;

Behr et al., 1969). CMA3 exhibits a yellow green fluorescence while DAPI exhibits dark

blue fluorescence when chromosomes after staining are irradiated with UV rays. After

staining with fluorochromes, it is therefore possible to characterize C-bands in terms of

base specificity. This allows better identification of homologous chromosomes and

results in construction of a reliable karyotype. There is still little information about

heterochromatin base composition in Heteroptera, i.e. whether the heterochromatin is rich

in A-T or G-C.

Manicardi and Gautam (1994), Madrioli et al. (1999 a & b) and Bizzaro et al.

(1999) employed A-T and G-C specific fluorochrome staining technique on some of the

Aphid species (Homoptera). In Heteroptera, such studies have been done by Perez et al.

(2000) and Severi-Aguiar et al. (2006) in Triatoma infestans and Triatoma vitticeps

(Reduviidae), by Ituarte and Papeschi (2004) in Tenagobia fuscata (Micronectidae), by

Grozeva et al. (2006) in Macrolophus costalis (Miridae), by Kuznetsova et al. (2007) in

Arachnocoris trinitatus (Pentatomidae) and by Bressa et al. (2008) in Holhymenia

rubiginosa (Coreidae). Grozeva et al. (2004) compared the fluorescent banding pattern in

four species of Nabidae viz. Nabis indicus, Nabis viridulus, Himacerus mirmicoides and

Prostemma guttala. Similar studies have been carried out by Bressa et al. (2005) in three

species of Coreidae (Athaumastus haematicus, Leptoglossus impictus and Phthia picta)

and one species each of Largidae (Largus rufipennis) and Rhopalidae (Jadera

sanguinolenta) respectively. Rebagliati et al. (2003) compared the fluorescent banding

patterns during meiosis in two species of Edessa (Pentatomidae), both having the same

chromosomal complement. Lanzone and Souza (2006 b), by applying fluorescent stains


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CMA3/DAPI, analyzed base specificity of C-heterochromatin in three species of

Antiteuchus viz., Antiteuchus mixtus, Antiteuchus sepulcralis and Antiteuchus macraspis

having same chromosomal number. In Triatoma vitticeps (Reduviidae) which has

multiple sex chromosomes (X1X2X3Y), the pattern of fluorescent banding has been used

to investigate the origin of multiple sex chromosome system by Severi-Aguiar et al.

(2006). Grozeva and Simov (2008) used fluorescent staining to identify two

morphologically close species of Cremnocephalus (Miridae). Kaur et al. (2010) observed

fluorescent banding pattern in two species of Dieuches (Lygaeidae).

Download - REVIEW OF LITERATURE - Shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/13745/8/08_chapter 2.pdf · REVIEW OF LITERATURE 15 REVIEW OF LITERATURE The Heteroptera is a numerically

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