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A comparative study of the chromosomes of eight genera of Indian Pyrgomorphinae (Acrididae)
Author(s) -
Rao T. Ramachandra
Publication year - 1937
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1050610202
Subject(s) - acrididae , biology , merge (version control) , autosome , chromosome , evolutionary biology , genetics , zoology , orthoptera , computer science , information retrieval , gene
In the spermatogonia of all the genera studied, there are nineteen rod‐shaped telomitic chromosomes, which differ considerably regarding their actual sizes in the different genera. However, an analysis of the measurements of second spermatocyte chromosomes shows that as regards proportional sizes and in seriation there is some degree of uniformity within the sub‐family. In Aularches, Atractomorpha, Chrotogonus, Colemania and Pyrgomorpha, the members of the smallest pair of autosomes appear as roundish or oval bodies and are comparable in shape, relative size and behavior with the ‘small’ dot‐like chromosomes of the general Acrididae, while in Orthacris and Zarytes they are not so and merge into the general series. The sex chromosome is the largest one in the complexes, or the second largest as in Poecilocerus. The usual forms of tetrads occur in the spermatocytes. It is found that the number of ring tetrads in any genus depends upon the length of its chromosomes; in genera with longer chromosomes there are more of them than in genera with shorter ones. While no final explanation has been offered regarding the chromosome relationship between this sub‐family and the other Acrididae, some points arising out of the present study have been briefly discussed, and it is shown that a simple process of elimination of two pairs is not sufficient to explain the smaller chromosome number in Pyrgomorphinae.