Gametic products transmitted by chickens heterozygous for chromosomal rearrangements.

Chromosomal analysis was made from 3744 chick embryos derived from reciprocal matings between parents, one of which was heterozygous for a pericentric inversion, a centric fission, or one of three translocations. The objectives were to determine the types and frequencies of genetically balanced and unbalanced gametes transmitted to early embryos by rearrangement heterozygotes and to ascertain if some gametic types were preferentially produced or utilized. The array of embryos obtained from the heterozygous sires did not deviate significantly from the expected, except in the case of the centric fission group.

The parental source of heteroploidy in chick embryos determined with chromosomally marked gametes.

Males homozygous for chromosomal translocations were mated to karyologically normal females. The resulting embryos, after incubation for 16-18 h, were prepared for cytogenetic analysis. Of the 62 embryos analysed, 54 (7.

Structural rearrangements of chromosomes in the domestic chicken: experimental production by X-irradiation of spermatozoa.

In order to produce chicks heterozygous for structural aberrations of chromosomes, 67 hens were inseminated with semen that had been exposed to 1200 R of X-rays. A sample of 204 chicks was hatched and survived. Among these, 18 (8.

Cytogenetic and phenotypic effects of a chromosomal rearrangement involving the Z-chromosome and micro-chromosome in the chicken.

Measurements demonstrated that the Z-chromosome was truly metacentric. Forty-six percent of one arm of a female's Z-chromosome had been translocated to a microchromosome (Z-micro) by irradiation of semen. The bread was 23 crossover units distal to the late feathering (K) locus.