S. S. Prabhu
Articles written in Journal of Genetics
Volume 38 Issue 1-2 July 1939 pp 177-191
In an attempt further to test Berg’s inference that there are “much more numerous sterility mutations in the
The results obtained show that such sex-specific dominant sterility mutations must be very rare, as compared with recessive sterility mutations of all kinds. Berg’s original conclusion, therefore, is confirmed.
Consideration of the data on sterility of the different classes of
By far the greater part of the sterility of the grandsons of irradiated males is due to sterility genes located in the
The present data, however, limit considerably more than those heretofore obtained the extent of the active region chiefly concerned in the
Volume 59 Issue 1 August 1964 pp 58-68
There is a considerable amount of interaction between the environment and the genetic factors controlling egg production In
The genes affecting egg production exhibit both additive genetic effects and dominant deviations. They also show non-allelic interactions. The non-allelic interaction between G and D results in low egg production.
An asymmetry in the distribution of positive and negative allels exists in the parents, which was understandable as three of the six lines included in the trial were selected for low egg production and the other three for high egg production.
There are probably present more dominant than recessive genes affecting egg Production in the parental stock used in these studies; the ratio of recessives to dominants being of the order of 1:4. Low egg production is due to recessive genes, high egg production to their dominant allels.
Dominance deviations present were largely unidirectional.
The order of dominance of the six lines used was D, B, E, C, A, F.
Volume 59 Issue 3 June 1966 pp 225-238
Volume 60 Issue 1 December 1968 pp 17-23
Volume 60 Issue 1 December 1968 pp 24-39
An investigation was carried out in
For keeping the X-chromosome intact, throughout the generations of testing, the balanced technique employing
Reciprocal crosses were made between N-8 and b-297. Repeated backcrosses were made of the resulting progeny to either of the two stock flies, selecting in each case, the female containing the marked chromosome till on an average 15/16 of the autosomes of one parental stock was replaced by those of the other parental stock, while the marked X-chromosome and an unmarked X-chromosome remained intact.
At each stage of backcrossing, observations were made on fecundity, egg-length, egg-volume (calculated) and hatchability.
Results showed that in case of fecundity, the genes affecting fecundity were not necessarily more numerous on the X-chromosome than in all the autosomes taken together as suggested by Berg (1937). In fact the data showed that the contribution of the autosomes is more than that of the X-chromosome. In case of egg-length and egg-volume there was evidence to suggest the presence of a few dominant genes radically affecting egg-length in the X-chromosome. This appeared to be so in a more pointed manner in case of hatchability which was a character with practically zero heritability.
Volume 60 Issue 1 December 1968 pp 69-79
The influence of sires on gestation periods of
Male and female calf bearing gestations were considered separately since significant differences existed between the two in the majority of cases. h2 (heritability estimate) was estimated by sib-analysis and the components of variance due to sire, dam and environment calculated, and the percentage contribution of each to the total variance estimated.
Significant variation in gestation period due to sire was found in
The contribution of the sire to the total variation in gestation period was also found to be small in general. The exceptions are the
Estimates of h2 for female births were found to be either zero, or small and negligible or large with large sampling errors that made the estimates undependable with the exception of
Volume 60 Issue 2 February 1970 pp 146-151
Isoimmunisations were done between pairs of
Blood typing of about 157 heads of
The frequency of occurrence for the
The comparisons of incidences of occurrence of blood-group factors for two herds each of
Volume 60 Issue 2 February 1970 pp 152-158
An investigation was carried out in
Reciprocal crosses were made between N-2 and G-l Hies. Selecting F-l females with the marked chromosome in one case, repeated backcrosses were made with N-2 males from stock and in another case with C-l males. In each generation, the fecundity and the hatchability were noted.
Results showed that the chromosome II contained genes for fecundity and hatchability which were more than in all the other chromosomes put together.
Volume 60 Issue 2 February 1970 pp 159-163
The haemoglobin variants in 371
Volume 60 Issue 2 February 1970 pp 164-174
Volume 60 Issue 2 February 1970 pp 184-191
Volume 60 Issue 3 September 1971 pp 207-213
Volume 60 Issue 3 September 1971 pp 214-221
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