Molecular Genetic Improvement of Wheat

1994 ◽  
pp. 539-547
Author(s):  
Indra K. Vasil ◽  
Vimla Vasil
2021 ◽  
Vol 28 (2) ◽  
pp. 128-134
Author(s):  
K. L AYORINDE ◽  
Y. SONG ◽  
P. DURMMOND ◽  
E. J. SMITH

Indigenous chickens obtained from the central and northern parts of Nigeria were evaluated for incidence and frequencies of endogenous viral, ev, genes 1, 3, 15 and 21 using blood samples collected by branchial venipuncture from free ranging adult birds of both sexes. Results indicated that 60.7% of the birds do not carry any of the four ev elements and that none of the birds carried genes for ev I. The frequencies ev 1, 3, 15 and 21 genes were 0.00, 0.07, 0.07 and 0.24. Significantly (P<0.05) higher frequencies of birds carrying the homozygous negative genes for each of the four ev elements are expected among the local chicken. Significantly (P<0.05) higher frequency of birds carrying the heterozygous than the homozygous positive forms for ev 3, 15 and 21 are also expected. The obtained negative genotypes agree closely with the expected, although slightly lower frequencies were obtained for ev 3 and 15 and higher frequeney for ev 21 than expected. However, there were no birds carrying the homozygous positive forms for ev 3 and ev 15 and slightly lower frequency for ev 21 than expected. The frequencies for the heterozygotes, though slightly lower for ev 21 and higher for ev 3 and 15, agree closely with the expected. Analysis of the DNA finger print, DFP, bands from RFLP studies indicated that the level of genetic diversity in the local chicken in Nigeria is only about 52%. The study suggests that there may be true genetic differences in the Nigerian local chicken population and hence the slightly high variation in genetic differences could be exploited for genetic improvement.


2005 ◽  
Vol 48 (3) ◽  
pp. 209-218 ◽  
Author(s):  
O. Distl

Abstract. Genetic improvement programmes in cattle have significantly contributed to the large increase in milk and meat production. As along with these breeding schemes top ranking AI sires are widely used and in the case, if these sires are carriers of mutated alleles, inherited defects can be widely disseminated. Most of the about 350 inherited anomalies in cattle occur at very low to low frequencies and thus, carriers are usually not detected in progeny tests based on reporting calves with congenital malformations. The molecular genetic decipherment of inherited anomalies is the necessary prerequisite for an efficient prevention of the dissemination of undesired alleles. The paper gives a survey on inherited anomalies being already characterized in cattle with molecular genetic methods. Furthermore, two genetic anomalies, namely congenital X-linked ectodermal dysplasia with hypotrichosis and missing teeth and bilateral convergent strabismus with exophthalmus are described in more detail.


Sign in / Sign up

Export Citation Format

Share Document