Variation in size of the dragonefly m-chromosome, with considerations on its significance for the chorogeography and taxonomy of the order odonata, and notes on the validity of the rule of reinig

Abstract

The morphological and kinetical features of the so-called m-chromosomes in dragonflies are reviewed. The relative size of the m-chromosomes varies in some species, but not in all. It has been demonstrated that the size is peculiar, in some dragonflies, for populations originating from different portions of the species range, and therefore it could be used to advantage in the taxonomy of infraspecific forms.The dragonfly m-chromosomes are considered as fragments of normal autosomes. The break can take place at any time, at any place in the holokinetic chromosome, and in any geographic population, therefore the variation in size of the m-chromosome is only accidental and has no chorogeographic implications.The chorogeographic hypothesis of REINIG (1938REINIG ( , 1939, which has been widely promoted by some distinguished odonatologists, has no connection with the size trend of the m-chromosomes. Its general validity for the determination of the body size of dragonflies is likewise rejected,

Intra and Interspecific Karyotype Variability in Five Species of Libellulidae (Anisoptera, Odonata)

“…reciprocal translocations, that change the relative size of those chromosomes. Likewise, when them chromosomes are present, they may vary in size among populations (KIAuTA 1968). Pantala flavescens and Erythemis attala illustrate these variations which are the most frequently found in the order.…”

“…The variations among populations which has been most frequently reported refer to the presence or absence of m chromosomes (microchromosomes of normal meiotic behavior) and to the differences in size of the bivalents they form (CRUDEN 1968;FERREIRA et al 1979;KIA.UTA 1968, 1972b, 1973, 1975KIAuTA andKIA.UTA 1980, 1983;SouzA BuENO 1982;YADAV 1979). Also, though less frequently, different haploid numbers have been observed among populations due to variation in the number of autosomes, regardless of m chromosomes (CRUDEN 1968;CUMMING 1964;]ENSEN and MAHANTY 1978;KlAUTA 1972bKlAUTA , 1975K:rAUTA and KlAUTA 1983;K:rAUTA and VON 0CHSSEE 1979;SouzA BuENO 1982).…”

Cytogenetic Characterization of Eight Odonata Species Originating from the Curonian Spit (the Baltic Sea, Russia) Using C-Banding and FISH with 18S rDNA and Telomeric (TTAGG)_n Probes

“…Since m-chromosomes are also missing (not found) in all other hitherto studied populations originating from geographically distant regions ( Table 1 ), this pattern is most likely characteristic of C. aenea in general. Although there are many records of m-chromosomes in the Odonata literature and speculations about their origin, size "polytypism," relationship with "normal" autosomes, meiotic behavior, patterns of distribution along the species range, possible roles in the evolution of the karyotypes, and taxonomic value [e.g., Kiauta, 1967aKiauta, , b, 1968bMola, 1996], this issue is still unresolved. Among insects, a peculiar pair of microchromosomes is known to be present in some true bug species (Heteroptera); however, m-chromosomes in Heteroptera seem to be different from those in Odonata.…”

“…The 18S rDNA probe was PCR amplified and labeled with biotin using the genomic DNA of the true bug Pyrrhocoris apterus (Linneus, 1758). The telomere probe (TTAGG) n was PCR amplified and labeled by rhodamine- Oksala, 1939Oksala, , 1945Makalovskaya, 1940;Kiauta, 1968b, c;Cruden, 1968 Oguma, 1915Oguma, , 1930Omura, 1955;Kiauta, 1968b 151 5-dUTP (GeneCraft, Germany). For primers, see Grozeva et al [2011].…”

“…A distinguishing cytogenetic feature of the Odonata karyotypes found in nearly 80% of the studied species is the presence of a minute pair of autosomes, so-called mchromosomes (= microchromosomes) whose origin and significance remain unclear [Kiauta, 1968b;De Gennaro et al, 2008]. A further peculiarity concerns the centromere structure of chromosomes in Odonata.…”