Synaptonemal complex analysis of hybrid cattle. II. Bos indicus × Bos taurus F1 and backcross hybrids

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 220-227 ◽  
Author(s):  
A. E. Dollin ◽  
J. D. Murray ◽  
C. B. Gillies

The levels of meiotic chromosome pairing abnormalities observed in six Australian F, Bos indicus x Bos taurus cattle crosses (mean = 23%) were significantly higher than those of the full-blood breeds (9%). The abnormal configurations in the F[hybrids included partial pairing failure, multivalents, interlocks, and inversion pairing. Abnormal configurations were also present, but at lower frequency, in backcross hybrid bulls. The main types of abnormal configurations and the levels of XY-autosomal associations and autosomal asynapsis observed were unlikely to cause significant fertility problems in the hybrids.Key words: synaptonemal complex, hybrid cattle, meiosis.

1990 ◽  
Vol 107 (1-6) ◽  
pp. 229-238 ◽  
Author(s):  
M. Switonski ◽  
H. A. Ansari ◽  
A. Matthew ◽  
H. R. Jung ◽  
G. Stranzinger

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 228-235 ◽  
Author(s):  
A. E. Dollin ◽  
J. D. Murray ◽  
C. B. Gillies

The mechanisms of homoeologous chromosome pairing were studied in synaptonemal complex (SC) spreads of F1 Brahman (Bos indicus) × Hereford (Bos taurus) cattle. The most common SC abnormalities were bivalents with partial pairing failure and interlocks. While C-band polymorphisms could underlie most of the SC abnormalities observed in the full-blood cattle, other causes seem also to be contributing in the hybrids. The pattern of the abnormalities indicates that genie differences between the species were probably involved. Pachytene substaging data suggest that in some spreads, early pachytene bivalents with partial pairing failure may achieve complete synapsis or may be converted to interlocks by late pachytene.Key words: synaptonemal complex, hybrid cattle, interlocks.


Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 856-864 ◽  
Author(s):  
A. E. Dollin ◽  
J. D. Murray ◽  
C. B. Gillies

Meiotic chromosome pairing abnormalities in full-blood and hybrid Bos taurus and B. indicus cattle have been surveyed by electron microscopy of pachytene synaptonemal complex spreads. In this paper, the full-blood spreads are described in detail, including the use of XY and nucleolar morphology and other measured parameters for pachytene substaging. Pairing abnormalities were observed in up to 9% of the full-blood spreads. Most of these pairing abnormalities (83%) occurred in early-pachytene spreads, suggesting that the mechanism of synaptic adjustment may operate in cattle.Key words: synaptonemal complex, cattle, pachytene substages.


Caryologia ◽  
2000 ◽  
Vol 53 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Marcia Denise Paixao Scavone ◽  
Claudio Oliveira ◽  
Luzia Aparecida Trinca ◽  
Fausto Foresti

Genome ◽  
1994 ◽  
Vol 37 (4) ◽  
pp. 672-678 ◽  
Author(s):  
K. Dai ◽  
A. E. Dollin ◽  
C. B. Gillies

Meiotic chromosome pairing behaviour in three normal sheep was surveyed by synaptonemal complex (SC) analysis at the electron microscope level. The SC karyotype of normal rams is composed of a sex pair, three metacentric or submetacentric pairs, and 23 acrocentric autosomal bivalents, with the total autosomal SC length ranging from 309 to 315 μm. Five nucleoli are terminally located on the three metacentric, and one large and one small acrocentric autosomal bivalents. XY morphology was used to divide pachytene into five substages. Although pairing abnormalities (mostly SC interactions) were recorded in an average of 16% of the spermatocytes, bivalent–XY association occurred in only 4.7% of the cells.Key words: sheep, synaptonemal complex, XY pair, pachytene substaging.


Copeia ◽  
1990 ◽  
Vol 1990 (4) ◽  
pp. 1122 ◽  
Author(s):  
Kent M. Reed ◽  
Philip D. Sudman ◽  
Jack W. Sites ◽  
Ira F. Greenbaum

Chromosoma ◽  
1982 ◽  
Vol 87 (2) ◽  
pp. 149-164 ◽  
Author(s):  
Terry Ashley ◽  
Liane B. Russell ◽  
N. L. A. Cacheiro

1991 ◽  
Vol 23 (Suppl 1) ◽  
pp. S222 ◽  
Author(s):  
DAF Villagomez ◽  
M Świtoński ◽  
B Singh ◽  
KRS Fisher ◽  
I Gustavsson ◽  
...  

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