Volume 83, Issue 1
April 2004, pages 1-108
pp 1-2 April 2004
pp 3-6 April 2004 Research Commentary
pp 7-8 April 2004 Research Commentary
pp 9-11 April 2004 Hypothesis
pp 13-15 April 2004 Commentary on J. Genet. Classic
pp 17-32 April 2004
pp 33-34 April 2004 Research Note
pp 35-38 April 2004 Research Article
Non-syndromic X-linked deafness is a rare form of genetic deafness in humans accounting for a small proportion of all hereditary hearing loss. Different clinical forms of non-syndromic X-linked deafness have been described, and most of these have been mapped. Here, we report a Chinese family affected by a congenital profound sensorineural hearing loss. All phenotypes of this family are clinically compatible with non-syndromic sensorineural deafness (DFN2). A maximum two-point Lod score of 2.32 was obtained at markerDXS6797 (θ = 0.00). Recombinants define a region of 4.3 cm flanked by markersDXS6799 andGATA172D05. This region overlaps the previously reported DFN2 region by 2.0 cm.
pp 39-48a April 2004 Research Note
Throughout human history, the region known today as the Anatolian peninsula (Turkey) has served as a junction connecting the Middle East, Europe and Central Asia, and, thus, has been subject to major population movements. The present study is undertaken to obtain information about the distribution of the existing mitochondrial D-loop sequence variations in the Turkish population of Anatolia. A few studies have previously reported mtDNA sequences in Turks. We attempted to extend these results by analysing a cohort that is not only larger, but also more representative of the Turkish population living in Anatolia. In order to obtain a descriptive picture for the phylogenetic distribution of the mitochondrial genome within Turkey, we analysed mitochondrial D-loop region sequence variations in 75 individuals from different parts of Anatolia by direct sequencing. Analysis of the two hypervariable segments within the noncoding region of the mitochondrial genome revealed the existence of 81 nucleotide mutations at 79 sites. The neighbour-joining tree of Kimura’s distance matrix has revealed the presence of six main clusters, of which H and U are the most common. The data obtained are also compared with several European and Turkic Central Asian populations.
pp 49-63 April 2004 Research Article
The extent of genetic polymorphism at fifteen autosomal microsatellite markers in 54 ethnically, linguistically and geographically diverse human populations of India was studied to decipher intrapopulation diversity. The parameters used to quantify intrapopulation diversity were average allele diversity, average heterozygosity, allele range (base pairs), and number of alleles. Multilocus genotype frequencies calculated for selected populations were utilized for testing conformity with the assumption of Hardy-Weinberg equilibrium. The exact test values, after Bonferroni correction, showed significant deviation amongst Gowda (vWA, Penta E); Dhangar, Satnami and Gounder (D8S1179); Hmar (FGA); Kuki and Balti (vWA) groups. Relatively low number of alleles and allelic diversity (base-pairs size) had been observed in populations of central India as compared with southern and northern regions of the country. The communities of Indo-Caucasoid ethnic origin and Indo-European linguistic family (Kshatriya of Uttar Pradesh) showed highest allelic diversity, as well as rare alleles, not reported in any other Indian populations. Analysis based on average heterozygosity was also found to be lowest among the populations of central India (0.729) and highest among the populations from north (0.777) and west (0.784) regions of the country, having Indo-Caucasoid ethnic origin and Austro-Asiatic linguistic affiliation. The maximum power of discrimination (85%-89%) had been observed at loci FGA, Penta E, D18S51 and D21S11, suggested high intrapopulation diversity in India. Genetic diversity revealed by STR markers was consistent with the known demographic histories of populations. Thus, the present study clearly demonstrated that the intrapopulation diversity is not only present at the national level, but also within smaller geographical regions of the country. This is the first attempt to understand the extent of diversity within populations of India at such a large scale at genomic level.
pp 65-71 April 2004 Research Article
Genotypes of 103 short tandem repeat (STR) markers distributed at an average of 40 cM intervals throughout the genome were determined for 40 individuals from the village of BirEl Hfai (BEH). This village of approximately 31.000 individuals is localized in the south-west of Tunisia. The allele frequency distributions in BEH were compared with those obtained for individuals in the CEPH (Centre d’Etude du Polymorphisme Humain) data using a Kolmo-gorov-Smirnov two-sample test. Fourteen out of the 103 markers (13.2%) showed significant differences (P<0.05) in distribution between the two populations. Population heterogeneity in BEH was indicated by an excess of observed homozygosity deviations from Hardy-Weinberg equilibrium at 3 loci (P<0.0005). No evidence for genotypic disequilibrium was found for any of the marker pairs. This demonstrated that in spite of a high inbreeding level in the population, few markers showed evidence for a different pattern of allelic distribution compared to CEPH.
pp 73-77 April 2004 Research Article
InD. melanogaster, the observation of greater pupation height under constant darkness than under constant light has been explained by the hypothesis that light has an inhibitory effect on larval wandering behaviour, preventing larvae from crawling higher up the walls of culture vials prior to pupation. If this is the only role of light in affecting pupation height, then various light : dark regimes would be predicted to yield pupation heights intermediate between those seen in constant light and constant darkness. We tested this hypothesis by measuring pupation height under various light : dark regimes in four laboratory populations ofDrosophila melanogaster. Pupation height was the greatest in constant darkness, intermediate in constant light, and the least in a light/dark regime of LD 14:14 h. The results clearly suggest that there is more to light regime effects on pupation height than mere behavioural inhibition of wandering larvae, and that circadian organization may play some role in determining pupation height, although the details of this role are not yet clear. We briefly discuss these results in the context of the possible involvement of circadian clocks in life-history evolution.
pp 79-99 April 2004 Review Article
Rice is an excellent system for plant genomics as it represents a modest size genome of 430 Mb. It feeds more than half the population of the world. Draft sequences of the rice genome, derived by whole-genome shotgun approach at relatively low coverage (4-6 X), were published and the International Rice Genome Sequencing Project (IRGSP) declared high quality (> 10 X), genetically anchored, phase 2 level sequence in 2002. In addition, phase 3 level finished sequence of chromosomes 1, 4 and 10 (out of 12 chromosomes of rice) has already been reported by scientists from IRGSP consortium. Various estimates of genes in rice place the number at >50,000. Already, over 28,000 full-length cDNAs have been sequenced, most of which map to genetically anchored genome sequence. Such information is very useful in revealing novel features of macroand micro-level synteny of rice genome with other cereals. Microarray analysis is unraveling the identity of rice genes expressing in temporal and spatial manner and should help target candidate genes useful for improving traits of agronomic importance. Simultaneously, functional analysis of rice genome has been initiated by marker-based characterization of useful genes and employing functional knock-outs created by mutation or gene tagging. Integration of this enormous information is expected to catalyze tremendous activity on basic and applied aspects of rice genomics.
pp 101-105 April 2004 Obituary
pp 107-108 April 2004 Obituary
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