Meiosis in rare males in parthenogenetic Cacopsylla myrtilli (Wagner, 1947) (Hemiptera, Psyllidae) populations from northern Europe

• Published in: Comparative Cytogenetics
• Main Authors: Christina Nokkala, Seppo Nokkala, Valentina Kuznetsova
• Format: Article in Journal/Newspaper
• Language: English
• Published: Pensoft Publishers 2013
• Subjects: Genetics; QH426-470; Norway; Northern Norway; Northern Sweden; Northwest Russia
• Online Access: https://doi.org/10.3897/compcytogen.v7i3.6126; https://doaj.org/article/f93dfc0265e24f0e8991a09ceae6d06f

For studying meiosis in males, large samples of Cacopsylla myrtilli (Wagner, 1947) (Hemiptera, Psyllidae) were collected in Norway, Sweden, Finland and northwest Russia. In addition to all-female populations, males were present in 10 out of 47 populations; still, all populations were highly female-biased, the proportion of males varying from 0.1% to 9.1%. These males are thus rare or so-called spanandric males. Males in northern Norway, Finland and northwest Russia showed normal chiasmate meiosis, while complete absence of chiasmata due to asynapsis was found in males collected in Norway and northern Sweden. In asynaptic meiosis, all univalent chromosomes divided during the first meiotic division resulting in incomplete second meiotic division and formation of diploid sperms. Hence, males in these populations are nonfunctional and do not contribute to the genetic constitution of the population, but appear in every generation as reversals from apomictic parthenogenesis and the mode of parthenogenesis is of obligatory type.