Revision of chromosome complement of an oriental bug Macrocheraia grandis (Gray, 1832) (Heteroptera: Pyrrhocoroidea: Largidae)

• Published in: Oriental insects Vol. 58; no. 4; pp. 569 - 584
• Main Authors: Gaba, Kalchana, Kaur, Harbhajan
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.10.2024
• Subjects: 4',6-diamidino-2-phenylindole; chromosome number; chromosomes; complement; diploidy; females; Heteroptera; intra-individual heterozygosity; Largidae; Macrocheraia grandis; males; meiosis; segregational disturbances; sex chromosomes; species; telophase
• ISSN: 0030-5316; 2157-8745; 2157-8745
• DOI: 10.1080/00305316.2024.2332598

Cytogenetic data of Macrocheraia grandis (Gray, 1832) have been a subject of much controversy as different diploid chromosome complements have been reported by different workers. In contrast to earlier studies claiming X0 and X 1 X 2 0 sex mechanism in males, our observations suggest the existence of multiple X and Y chromosomes. On the basis of an exhaustive study of 457 well spread different stages, examination of the entire male meiotic cycle up to telophase II and study of the spermatogonial and oogonial complement we decided the chromosome complement to be 2n (male) = 12A+2m+X m Y n , with m+n  = 3, 5 or 7 and 2n (female) = 12A+2m+X m X n with m+n  = 2, 3, 6 or 8 where m and n are the number of maternal and paternal sex chromosomes. Our data are further supplemented with banding techniques. Besides, the presence of a conspicuous autosomal bivalent, DAPI bright microchromosomes and presence of remnant nucleolar bodies up to diplotene are worth mentioning features of the species.