Volume 83, Issue 3
December 2004, pages 223-295
pp 223-226 December 2004 Research Commentary
pp 227-230 December 2004 Research Commentary
pp 231-233 December 2004 Commentary on J. GENET. Classic
pp 235-244 December 2004
The rate of mutation at which the gene for haemophilia appears in the population of London is estimated at about once in 50,000 human life cycles. There are probably two distinct allelomorphs at the same locus, the milder type arising less frequently by mutation than the severe type.
I have to thank Dr Julia Bell and Dr C. V. Green for most generously placing at my disposal data collected on behalf of the Medical Research Council and the Research Committee of the American Medical Association.
pp 245-250 December 2004 Research Article
We describe tests for detecting and locating quantitative trait loci (QTL) for traits in Hanwoo cattle. From results of a permutation test to detect QTL for marbling, we selected the microsatellite locus ILSTS035 on chromosome 6 for further analysis. K-means clustering analysis applied to five traits and nine DNA markers in ILSTS035 resulted in three cluster groups. Finally we employed the bootstrap test method to calculate confidence intervals using the resampling method to find major DNA markers. We conclude that the major markers of ILSTS035 locus on chromosome 6 of Hanwoo cattle are markers 235 bp and 266 bp.
pp 251-255 December 2004 Research Article
While most men prefer women as their sexual partners, some are bisexual and others are homosexuals. It has been debated for a long time whether a person’s sexual preference is innate, learned, or due to a combination of both causes. It was recently discovered that the human right-versus-left-hand use preference and the direction of scalp hair-whorl rotation develop from a common genetic mechanism. Such a mechanism controls functional specialization of brain hemispheres. Whether the same mechanism specifying mental makeup influences sexual preference was determined here by comparing hair-whorl rotation in groups enriched with homosexual men with that in males at large. Only a minority of 8.2% (n = 207) unselected ‘control’ group of males had counterclockwise rotation. In contrast, all three samples enriched with homosexual men exhibited highly significant (P< 0.0001), 3.6-fold excess (29.8%,n = 272) counterclockwise rotation. These results suggest that sexual preference may be influenced in a significant proportion of homosexual men by a biological/genetic factor that also controls direction of hair-whorl rotation.
pp 257-263 December 2004 Research Article
We have cloned a novel gene,Cymg1 (GenBank accession number AY600990), from a mouse testis cDNA library.Cymg1 is located in 2G3 of mouse chromosome 2. The cDNA includes an open reading frame that encodes 141 amino acid residues. The encoded polypeptide has a cysteine protease inhibitor domain found in the family 2 cystatins but lacks critical consensus sites important for cysteine protease inhibition. These characteristics are seen in the proteins of the CRES subfamily of the family 2 cystatins which are expressed specifically in the reproductive tract. CYMG1 protein shows 44% identity with mouse CRES and 30% identity with mouse cystatin C. Northern blot analysis showed that theCymg1 gene was specifically expressed in adult mouse testis. RT-PCR also showed thatCymg1 was expressed in testis and spermatogonial cells.Cymg1 expression level varied in the different developmental stages of mouse testis, and were coincidental with spermatogenesis and sex maturation. These results indicate thatCymg1 may play important roles in mouse spermatogenesis and sex maturation
pp 265-277 December 2004 Research Article
What are the genetics of phenotypes other than fitness, in outbred populations? To answer this question, the quantitative-genetic basis of divergence was characterized for outbredDrosophila melanogaster populations that had previously undergone selection to enhance characters related to fitness. Line-cross analysis using first-generation and second-generation hybrids from reciprocal crosses was conducted for two types of cross, each replicated fivefold. One type of cross was between representatives of the ancestral population, a set of five populations maintained for several hundred generations on a two-week discrete-generation life cycle and a set of five populations adapted to starvation stress. The other type of cross was between the same set of ancestral-representative populations and another set of five populations selected for accelerated development from egg to egg. Developmental time from egg to eclosion, starvation resistance, dry body weight and fecundity at day 14 from egg were fit to regression models estimating single-locus additive and dominant effects, maternal and paternal effects, and digenic additive and dominance epistatic effects. Additive genetic variation explained most of the differences between populations, with additive maternal and cytoplasmic effects also commonly found. Both within-locus and between-locus dominance effects were inferred in some cases, as well as one instance of additive epistasis. Some of these effects may have been caused by linkage disequilibrium. We conclude with a brief discussion concerning the relationship of the genetics of population differentiation to adaptation.
pp 279-283 December 2004 Research Note
pp 285-289 December 2004 Research Note
pp 291-295 December 2004 Research Note
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