Synapsis with and without recombination in the male meiosis of the leaf-footed bug Holhymenia rubiginosa (Coreidae, Heteroptera).
In organisms with chiasmatic meiosis two different relationships have been described between crossing over and synapsis: in one group of organisms synapsis depends on the initiation of meiotic recombination while in the other group it is independent of this initiation. These patterns have been observed mainly in organisms where all meiotic bivalents in the set have similar behaviors. In some heteropteran insects a pair of chromosomes named m chromosomes is known to behave differently from autosomes regarding synapsis and recombination. Here we used immunodetection of a synaptonemal complex component and acid-fixed squashes to investigate the conduct of the small m chromosome pair during the male meiosis in the coreid bug Holhymenia rubiginosa. We found that the m chromosomes form a synaptonemal complex during pachytene, but they are not attached by a chiasma in diakinesis. On the other hand, the autosomal bivalents synapse and recombine regularly. The co-existence of these variant chromosome behaviors during meiosis I add further evidence to the absence of unique patterns regarding the interdependence of synapsis and recombination.
Toscani
María Ayelén
MA
Laboratorio de Citogenética y Evolución, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, UBA, Intendente Güiraldes 2620, Pabellón 2-piso 4, Buenos Aires C1428EHA, Argentina.
Pigozzi
María Inés
MI
Bressa
María José
MJ
Papeschi
Alba G
AG
D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D023902:Chromosome Pairing / Q000235:genetics; D005260:Female; D006416:Hematoxylin; D020062:Heteroptera / Q000166:cytology* / Q000235:genetics* / Q000378:metabolism; D008297:Male; D011995:Recombination, Genetic / Q000235:genetics*; D013090:Spermatocytes / Q000378:metabolism; D013194:Staining and Labeling; D013573:Synaptonemal Complex / Q000378:metabolism; D014960:X Chromosome / Q000378:metabolism
D002868:Chromosomal Proteins, Non-Histone; D006416:Hematoxylin