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

ABSTRACT

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 X₁X₂0 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_mY_n, with _m+n = 3, 5 or 7 and 2n (female) = 12A+2m+X_mX_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.

KEYWORDS:

• Largidae
• sex chromosomes
• intra-individual heterozygosity
• segregational disturbances
• Heteroptera

Acknowledgements

The authors are thankful to the Department of Zoology & Environmental Sciences, Punjabi University Patiala for providing lab facilities to conduct this experimental work. One of the authors thankfully acknowledges UGC-BSR fellowship (fellowship No. 5855) for providing financial support for the work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by UGC-BSR fellowship [fellowship No. 5855]. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.