The goal of the present study was to narrow a region of chromosome 13 to only several genes and then apply unbiased statistical approaches to identify molecular networks and biological pathways relevant to blood-pressure salt sensitivity in Dahl salt-sensitive (SS) rats. The analysis of 13 overlapping subcongenic strains identified a 1.37 Mbp region on chromosome 13 that influenced the mean arterial blood pressure by at least 25 mmHg in SS rats fed a high-salt diet. DNA sequencing and analysis filled genomic gaps and provided identification of five genes in this region, Rfwd2, Fam5b, Astn1, Pappa2, and Tnr. A cross-platform normalization of transcriptome data sets obtained from our previously published Affymetrix GeneChip dataset and newly acquired RNA-seq data from renal outer medullary tissue provided 90 observations for each gene. Two Bayesian methods were used to analyze the data: 1) a linear model analysis to assess 243 biological pathways for their likelihood to discriminate blood pressure levels across experimental groups and 2) a Bayesian graphical modeling of pathways to discover genes with potential relationships to the candidate genes in this region. As none of these five genes are known to be involved in hypertension, this unbiased approach has provided useful clues to be experimentally explored. Of these five genes, Rfwd2, the gene most strongly expressed in the renal outer medulla, was notably associated with pathways that can affect blood pressure via renal transcellular Na(+) and K(+) electrochemical gradients and tubular Na(+) transport, mitochondrial TCA cycle and cell energetics, and circadian rhythms.

Renin was the first blood pressure (BP) quantitative trait locus (QTL) mapped by linkage analysis in the rat. Subsequent BP linkage and congenic studies capturing different portions of the renin region have returned conflicting results, suggesting that multiple interdependent BP loci may be residing in the chromosome 13 BP QTL that includes Renin. We used SS-13BN congenic strains to map 2 BP loci in the Renin region (chr13:45.2–49.0 Mb). We identified a 1.1 Mb protective Brown Norway (BN) region around Renin (chr13:46.1–47.2 Mb) that significantly decreased BP by 32 mmHg. The Renin protective BP locus was offset by an adjacent hypertensive locus (chr13:47.2–49.0 Mb) that significantly increased BP by 29 mmHg. Sequence analysis of the protective and hypertensive BP loci revealed 1,433 and 2,063 variants between Dahl salt-sensitive/Mcwi (SS) and BN rats, respectively. To further reduce the list of candidate variants, we re-genotyped an overlapping SS-13SR congenic strain (S/renrr) with a previously reported BP phenotype. Sequence comparison between SS, Dahl R (SR), and BN reduced the number of candidate variants in the 2 BP loci by 42% for further study. Combined with previous studies, these data suggest that at least 4 BP loci reside within the 30 cM chromosome 13 BP QTL that includes Renin.

Inheritance and linkage relationships were studied for six morphological characters in a cross between Arachis monticola Krap . et Rig . and A . hypogaea L . All the characters were found to be governed by single dominant genes . The genes governing leaflet krinkling and peg pigmentation assorted independently while the genes for four pod characters viz . catenate nature, beak, reticulation and thin pericarp showed linkage . A linkage map for these genes was proposed .

Toxicity of an organochloride insecticide, hexachlorocyclohexane (HCH) on the alterations in the growth and silk qualities of silkworm, Bombyx mori L were investigated. HCH yielded higher growth constants (K), indicating impairment of growth of silkworms and silk gland. The decrement in fibroin content is significant. HCH treatment also resulted in considerable reduction in the cocoon, pupal and shell weights, survival and emergence of pupae and number of eggs laid and deterioration in quality and quantity of silk thread.

The progress in genetic improvement of groundnut in India during the last five decades has been possible largely due to understanding and utilizing the information generated on the genetics of various characters of the plant. The current genetic studies on groundnut in India are carried out both on qualitative and agronomically important quantitative characters. Research accomplishments which are noteworthy in these areas have been reported in this paper. However, the genetics of several characters of economic importance has not been analyzed so far. Efforts to incorporate resistance to abiotic and biotic factors have gained momentum and a large number of resistant sources have been identified for each of these constraints. Additional efforts are expected to be made on gaining insight into the genetics of resistance to abiotic stresses and insect pests among biotic stresses, where the available information is meagre. Future studies are also expected to concentrate on unravelling the relationship of economic yield with various other characters, including the physiological and biochemical ones. Molecular marker techniques hold promise for genetic analysis of groundnut, as in other crop plants.