Accession Number:

AD0671657

Title:

KARYOLOGICAL STUDY OF SOME ACARI AND THE PROBLEM OF SEX DETERMINATION IN THE GROUP,

Descriptive Note:

Corporate Author:

ARMY BIOLOGICAL LABS FREDERICK MD

Personal Author(s):

Report Date:

1968-01-01

Pagination or Media Count:

12.0

Abstract:

The karyologic peculiarities of the sperm cells of four Tyroglyphoid mite species was investigated. The following karyotypes were found in Glycyphagus domesticus fam. Glycyphagidae eight bivalents X-chromosome in Tyroglyphus farinae and Tyrophagus noxius fam. Tyroglyphidae, subfam. Tyroglyphinae corresponding eight bivalents X-chromosome and seven bivalents X-chromosome were established. Thus, in these three species the male sex must be regarded as heterogametic, and sex determination in them most probably belongs to the Protenor-type. There are ten spermatogonial chromosomes and five bivalents in spermatocytes of Rhizoglyphys echinopus fam. Tyroglyphidae, subfam. Rhizoglyphinae. Sex chromosomes are absent here. In Ixodes ricinus Ixodidae, spermatocytes increases greatly in size during the prolonged growth period, and it is also at this stage that the nucleus passes the phase of the germinal vesicle. The spermatogonia show the diploid number of 2n28 chromosomes 26 X Y, but in the spermatocytes the haploid number is n14 13 XY. The chromosomes are large and differ greatly in size and configuration. The XY pair represents the smallest pair, and the X exceeds the Y-chromosome by two or three times in length. Their first division is reductional and the second equational. Sex determination belongs to the Lygaeus type. Author

Subject Categories:

  • Anatomy and Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE