Dynamic meiotic behavior and evolutionary insights of supernumerary B chromosomes in the hangingfly <i>Bittacuscirratus</i> (Mecoptera, Bittacidae).

ABSTRACT: Supernumerary B chromosomes are significant dispensable genetic elements that follow their own species-specific evolutionary pathways. Despite their widespread occurrence, comprehensive analyses of their meiotic behavior remain limited. In this study, we present the first systematic investigation of B chromosome morphology and meiotic behavior in the hangingfly Bittacuscirratus Tjeder, 1956 using cytogenetic approaches. The male basal chromosome numbers of B.cirratus is 2n = 30 + XO, with 0-5 polymorphic B chromosomes. Intraspecific B chromosome polymorphism manifests as various distinct morphotypes ranging from punctiform, bicentric, and ring-shaped to larger coiled forms, indicating that the B chromosomes may undergo rapid structural changes. During meiosis, B chromosomes d

SUBMITTER: He LL 

PROVIDER: S-EPMC12159664 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature