Comparative study of biological and technological characters in three generations of silkworm Bombyx mori L. ameiotic, parthenogenetically cloned lines.

Purpose: Detect any deviation in biologic and technologic characters of eight ameiotic-parthenogenetically cloned lines of Bombyx mori L. from different origins from a normal sexually reproduced control line in three generations.

Methods: Comparative study of the three generations was conducted in SES, Vratza, unit of the National Center for Agrarian Sciences of Bulgaria after fixing all environmental rearing conditions.

[Sperm foreward movement in the female genital tract of sheep].

Investigations were carried out to establish the effect of deep freezing, extent of dilution, and site of applying the spermatozoa as well as the functional state of the female genital apparatus of sheep on the forward movement of spermatozoa. It was found that at the insemination of ewes with freshly obtained undiluted semen at the 30th min following insemination there were single live spermatozoa, in the oviducts their number gradually increased up to the fourth hour, reaching several thousand. The highly diluted semen was found to produce an unfavourable effect on the movement of spermatozoa.

[Complex-forming factors in the dilution of bull sperm for deep freezing].

Micro- and ultramicroelectrophoresis on Cellogel were employed to study the formation of complexes of bull's semen and the constituents of Nagaze-Niva's extender in all possible combinations. It was found that a new glycoprotein complex is formed in mixing the semen with yolk. This complex was found to bind 82 +/- 1.