Identification of sperm motility markers in bovine transition protein genes

Transition proteins (TNPs) are essential in chromatin condensation during spermiogenesis, and hence, they are the candidate genes for identifying sperm motility markers. Coding and in silico predicted promoter regions of these genes were investigated in crossbred and purebred cattle, and also, their mRNA quantification was done to explore its use as a diagnostic tool of infertility. PCR‐SSCP analysis revealed two band patterns in fragment III of TNP1 and fragment II of TNP2 gene. Sequence analysis revealed a deletion of “G” nucleotide in 3′UTR region of TNP1 and C>T SNP in intronic region of TNP2 gene. Least square analysis of variance did not reveal any significant influence of nucleotide deletion on any sperm motility parameters in both crossbred and purebred cattle. However, C>T SNP had a significant effect on initial progressive motility (p < 0.05) in purebred cattle and post‐thaw motility in overall cattle population. RT‐qPCR analysis did not reveal any significant variation in TNP1 and TNP2 gene expression among poorly motile and good quality spermatozoa of Vrindavani bulls.     

Isolation of two cDNAs encoding MHC-DQA1 and -DQA2 from the water buffalo, Bubalus bubalis

In the present study, we explored structural and functional variations and possible duplication of the major histocompatibility complex (MHC)-DQA gene in water buffalo (Bubalus bubalis). Two cDNA sequences, amplified from one individual water buffalo, were designated as Bubu-DQA1 (DQA*0101) and -DQA2 (DQA*2001). The percentage of nucleotide and amino acid similarity between Bubu-DQA1 and -DQA2 revealed that these sequences display more similarity to alleles of respective DQA1 and DQA2 genes from other ruminant species than to each other. The phylogenetic analysis also revealed a considerably larger genetic distance between these two genes than between homologous genes from other species. The larger genetic distance between DQA*0101 and DQA*2001, and the presence of different bovine DQA putative locus specific amino acid motifs, suggests these sequences are non-allelic. This finding is consistent with DQA gene duplication in other ruminants.     

Effect of host plants on fitness traits and detoxifying enzymes activity of Helopeltis theivora, a major sucking insect pest of tea

Helopeltis theivora Waterhouse (Heteroptera: Miridae) is a major sucking insect pest of tea (Camellia sinensis) which feeds on a wide variety of alternative host plants. Feeding biology and fitness traits of H. theivora, on two alternative host plants, viz., Mikania micrantha (Asteraceae) and Psidium guajava (Myrtaceae), besides C. sinensis (Theaceae), were studied along with corresponding levels of xenobiotic defense enzymes. C. sinensis is the preferred host of H. theivora. The development time of H. theivora is significantly shorter on C. sinensis (13.3?±?0.16?days) than on the two other hosts, M. micrantha (14.2?±?0.22?days) and P. guajava (14.7?±?0.23?days). Similarly, the fecundity (C. sinensis: 172.6?±?4.5 eggs/female, M. micrantha: 128.6?±?4.4 eggs/female, P. guajava: 118.7?±?3.3 eggs/female), oviposition period (C. sinensis: 24.1?±?0.7?days, M. micrantha: 22.5?±?0.6?days, P. guajava: 21.7?±?0.8?days) and hatchability (C. sinensis: 80.9?±?1.9%, M. micrantha: 69.4?±?1.6%, P. guajava: 64.1?±?1.7%) are recorded to be significantly higher on C. sinensis. The age at reproductive maturity and egg incubation periods were lower on C. sinensis than on the two other host plants. Host-based variation in H. theivora fitness traits is interpreted in light of differential activity of three principal xenobiotic detoxifying enzymes, the general esterases (GEs), glutathione S-transferases (GSTs) and cytochrome P450 monooxygenases (CYPs). The activities of these enzymes in H. theivora were significantly enhanced when the insect fed on M. micrantha and P. guajava as compared with on C. sinensis.     

Seasonal incidence and enzyme-based susceptibility to synthetic insecticides in two upcoming sucking insect pests of tea

Climate change, deforestation and over reliance on chemical pesticides during the last five decades are presumed to have had a significant impact on the incidence and abundance of agricultural pests. The thrips (Scirtothrips dorsalis Hood) and the greenfly (Empoasca flavescens Fabricius), which were previously considered as minor or occasionally as serious pests in localized areas of tea plantations, are now established as regular and at times major pests in tea plantations of North Bengal spread over the sub Himalayan slopes and the adjoining plains of Terai and the Dooars. Tea-planters from different pockets of North Bengal have been repeatedly reporting control failures of these pests with the use of insecticides in recommended dilutions. A study of their seasonal incidence along with activity of detoxifying enzymes was considered. The trend of a recent population study revealed that E. flavescens and S. dorsalis were abundant throughout the year, with peaks during April to June. Abiotic factors such as temperature, rainfall, sunshine hours and relative humidity (afternoon) influenced the population abundance. Insecticide-exposed populations showed higher levels of activity of the detoxifying enzymes than those collected from organic plantations and the laboratory-reared populations that had not been exposed to insecticides. Detoxifying enzymes in insecticide-exposed E. flavescens collected from Terai and the Dooars as compared with laboratory control specimens showed 3.0–5.2 and 3.0–9.7-fold increases in general esterases (GEs), 1.5–4.8 and 3.6–5.3-fold increases in cytochrome P450s (CYPs) and 1.2–3.5 and 1.5–2.5-fold increases in glutathione-s-transferases (GSTs), respectively. Similarly, S. dorsalis collected from Terai and the Dooars showed 2.0–6.0 and 2.3–5.6-fold increases in GEs, 1.5–2.3 and 1.6–2.4-fold increases in CYPs and 2.6–3.7 and 2.3–3.6-fold increases for GSTs, respectively. Bands of isozymes of esterase I–VI and I–V were found to be expressed in insecticide-exposed specimens whereas a negligible expression was evident for the bands in unexposed E. flavescens and S. dorsalis of organic plantations and laboratory-reared origins, respectively. The data obtained in the present study would be useful in developing the integrated resistance management strategies leading to effective management of the said pests.     

Plate tectonics 2.5 billion years ago: evidence at kolar, South India

The Archean Kolar Schist Belt, south India, is a suture zone where two gneiss terranes and at least two amphibolite terranes with distinct histories were accrted. Amphibolites from the eastern and western sides of the schist belt have distinct incompatible element and isotopic characteristics sugesting that their volcanic protoliths were derived from dint mantle sources. The amphibolite and gneiss terranes were juxtaposed by horizontal compression and shearing between 2530 and 2420 million years ago (Ma) along a zone marked by the Kolar Schist Belt. This history of accretion of discrete crustal terranes resembles those of Phanerozoic convergent margins and thus suggests that plate tectonics operated on Earth by 2500 Ma.     

Integrated nutrient management (INM) on yield trends and sustainability,nutrient balance and soil fertility in a long-term (30 years) rice-wheat system in the Indo-Gangetic plains of India

We analyzed data from a long-term rice–wheat cropping sequence to evaluate the effects of integrated nutrient management (INM) on yield trends and sustainability, nutrient balance and soil fertility of the system. After 30th cycle, grain yield of both the crops significantly declined under control and highest rice and wheat grain yields were obtained when 50% N supplied through green manure and farm yard manure, respectively. The magnitude of yield slope under INM was found considerably higher than 100% recommended fertilizer (RDF). Sustainable yield index (SYI) for both the crops were found lower in control but considerably higher with the 100% RDF and under INM. The soils under all the treatments suffered an apparent loss of K and N (except where organics replacing 50% N). Correlation study also reveals K is the sole factor for the yield sustainability as apparent K balance was negatively correlated with SYI and yield slope.