Zoology

To study the possible effect of leptin on PRL and insulin-like growth factor (IGF)-I secretion from rat endometrial stromal cells. Design: The effect of recombinant murine leptin on the secretion of PRL and IGF-I by cultured rat endometrial cells was investigated. Setting: Academic institutions. Animal(s): Laboratory bred virgin female rats aged 3-4 months. Intervention(s): Endometrial stromal cell (ESC) cultures in the fourth passage stimulated with 1-1,000 ng/mL of leptin for 24 hours and with 1 ng/mL leptin for 24 -72 hours. Main Outcome Measure(s): Measurement of PRL and IGF-I levels in the conditioned media by enzyme immunoassay.

The mainly fresh water arboviral vector Aedes aegypti L. (Diptera: Culicidae) can also undergo pre-imaginal development in brackish water of up to 15 ppt (parts per thousand) salt in coastal areas. We investigated differences in salinity tolerance, egg laying preference, egg hatching and larval development times and resistance to common insecticides in Ae. aegypti collected from brackish and fresh water habitats in Jaffna, Sri Lanka. Brackish water-derived Ae. aegypti were more tolerant of salinity than fresh water-derived Ae. aegypti and this difference was only partly reduced after their transfer to fresh water for up to five generations. Brackish water-derived Ae. aegypti did not significantly discriminate between 10 ppt salt brackish water and fresh water for oviposition, while fresh water-derived Ae. aegypti preferred fresh water. The hatching of eggs from both brackish and fresh water-derived Ae. aegypti was less efficient and the time taken for larvae to develop into pupae was prolonged in 10 ppt salt brackish water. Ae. aegypti isolated from coastal brackish water were less resistant to the organophosphate insecticide malathion than inland fresh water Ae. aegypti. Brackish and fresh water-derived Ae. aegypti however were able to mate and produce viable offspring in the laboratory. The results suggest that development in brackish water is characterised by pertinent biological changes, and that there is restricted genetic exchange between coastal brackish and inland fresh water Ae. aegypti isolates from sites 5 km apart. The findings highlight the need for monitoring Ae. aegypti developing in coastal brackish waters and extending vector control measures to their habitats.

Mankind has been interested in sex preselection since ancient times. It can be achieved either by sexing of early embryos or by separation of X and Y chromosome-bearing spermatozoa, but new separation techniques with better accuracy and low costs are necessary. The objective of this study was to fractionate X and Y-bearing bovine sperm using sucrose gradient. A discontinuous sucrose density gradient was prepared by layering successive decreasing sucrose solution upon one another. Finally 20μL semen sample was loaded on the top layer. Then it was centrifuged at 500 x g for 12 minutes at room temperature. After elution of fractions and centrifugation (at 700 x g for 5 minutes), sperm viability and acrosome integrity were assessed by using 0.4% Trypan Blue and 0.75% Giemsa stain. Other part of the pellet was stained with 2% orcein red for 30 minutes to obtain sets of chromosomes. Repeated measures analysis of variance (ANOVA) with Bonferroni's multiple comparison test was performed to compare the percentages of female sperms at every layer. Results have shown that means of percentage of X chromosomes increased from layer 1 (15.55 ± 2.939 %), layer 2 (14.0 ± 3.055%), layer 3(26.33 ± 0.881%) to layer 4 (31.85 ± 5.186), but there is a statistically significant difference between layer 2 and layer 4 (P<0.05). However it needs to perform further studies to obtain appropriate density gradient model. Our present study demonstrates that the discontinuous sucrose density gradients can be considered as low cost tool for sperm sexing of bovine semen.

Artificial Insemination (AI) with frozen semen has been proved as the most potent method for rapid genetic improvement in domestic animals. While the use of AI with fresh semen is limited by the restricted period of sperm viability, this limitation may be overcome by the storage of frozen semen. Recently AI center of Thirunelvely is being advised to use the deep-frozen semen processed from Kundasale of Central Province (CP) for AI purposes. Thus the present study was undertaken to compare the quality of locally produced stored semen (LPS) and semen brought from Kundasale in deep-frozen condition (KDFS) by assessing the viability of them as the prominent factor that determine the successful of AI service . A batch of LPS and KDFS was obtained from the AI center at Thirunelvely. LPS was diluted with 2.9% sodium citrate buffer solution to evaluate the individual progressive motility and sperm velocity, sperm morphology, and acrosome integrity. Sperm smear was prepared by using 1% eosin and 0.75% Giemsa stain to identify intact and reacted acrosome and sperm abnormalities respectively. Thawed semen was also assessed for motility examination, percentage of intact acrosome, viability and morphology. Paired t test was performed to compare the means of the viability of LPS and KDFS (P<0.05). Even though the viability and sperm velocity of KDFS (84.57 ± 0.9957%, 24.75 ± 1.887 m/s) was lower than LPS (96.62 ± 0.7837%, 26.00 ± 1.581 m/s), its viability is enough for successful conception rate. Therefore usage of KDFS instead of LPS won t affect the successful rate of AI service in Jaffna Peninsula.

BackgroundAedes aegyptimosquito, the principal global vector of arboviral diseases, lays eggs and undergoes larval and pupal development to become adult mosquitoes in fresh water (FW). It has recently been observed to develop in coastal brackish water (BW) habitats of up to 50% sea water, and such salinity tolerance shown to be an inheritable trait. Genomics of salinity tolerance inAe. aegyptihas not been previously studied, but it is of fundamental biological interest and important for controlling arboviral diseases in the context of rising sea levels increasing coastal ground water salinity.ResultsBW- and FW-Ae. aegyptiwere compared by RNA-seq analysis on the gut, anal papillae and rest of the carcass in fourth instar larvae (L4), proteomics of cuticles shed when L4 metamorphose into pupae, and transmission electron microscopy of cuticles in L4 and adults. Genes for specific cuticle proteins, signalling proteins, moulting hormone-related proteins, membrane transporters, enzymes in...

Aedes aegypti is considered the principal vector of several human arboviral diseases, including dengue, chikungunya, West-Nile encephalitis and Zika. Many of the approximately 5% of mosquito species that are salin-ity tolerant 1 , are vectors of important human and animal diseases; and such vectors can increase in number and invade to new territories in the context of global warming and other anthropogenic environmental changes 2-4. Aedes aegypti has previously been regarded to oviposit and undergo preimaginal development only in fresh water (FW) collections, and hence, larval control efforts are solely directed towards FW habitats in the vicinity of human dwellings 5-6. We recently showed that Ae. aegypti and the closely related arboviral vector Ae. albopictus can undergo preimaginal development in brackish water (within discarded food and beverage containers) of up to 15 parts per thousand (ppt) salt and 14 ppt salt, respectively in northern Sri Lankan beaches 7-8. Saline, brackish water (BW) and FW are defined as containing >30, 0.5-30 and <0.5 ppt salt, respectively in this context 2. Aedes ae-gypti larvae have also been observed in brackish domestic wells of up to 9 ppt salt in the coastal Jaffna peninsula of northern Sri Lanka 9. Similarly, BW development of Ae. aegypti or Ae. albopictus has been observed in coastal locations of Brunei Darussalam 10 , USA 11 and Brazil 12. Physiological changes accompanying BW adaptation in Ae. aegypti include the greater ability to oviposit in 10 ppt salinity; and significantly greater, and partly inheritable, larval salinity tolerance 13. The anal papillae of Ae. aegypti are reported to transport Na + and Cl-from a FW environment into the hemolymph 14-15. There is also a salinity-related differential expression of specific aquaporins in Ae. aegypti anal papillae 16. These findings suggest a possible role of anal papillae in short-term osmoregulation in Ae. aegypti lar-vae. In an attempt to explore the mechanisms, underlying the adaptation to BW, this study investigated the changes in anal papillae size in Ae. aegypti mosquitoes adapting to BW. Self-mating laboratory colonies of Ae. aegypti were established from larvae collected from FW ovitraps in Thirunelvely (9° 41' N: 80° 1' E) and BW domestic wells in coastal Kurunagar (9° 39' N: 80° 1' E) in the Jaffna peninsula of Sri Lanka. The FW colony was maintained in potable tap water supplied from a dug-well located in the University of Jaffna campus in Thirunelvely, and the BW colony in sea water collected from Jaffna lagoon, diluted with tap water to yield ~10 ppt salt (measured by a refrac-tor Salinometer, Atago, Japan). The adult and larvae were maintained at 28-30°C with relative humidity ~75% and 12 h dark and light conditions. Eggs from the BW and FW colonies were collected in 10 ppt saline BW and 0 ppt saline FW egg-laying surfaces, respectively and allowed to hatch into larvae in the corresponding BW and FW. Larvae were reared in 24 × 16 cm plastic trays with 1.5 litre water with maximum number of 150 larvae per tray and fed with fish meal powder thrice a day. Adult females were blood-fed on mice according to a protocol approved by the Institutional Animal Ethics Review Committee of the University of Jaffna (June, 2014; AERC/2014/02). The FW colony maintained up to 20 generations in the laboratory and BW colony maintained up to 24 generations were used for experimental purposes. For experiments to determine the effects of reversing larval rearing salinity (salinity reversal experiments), FW colony eggs were collected on FW egg-laying surfaces and then reared in 10 ppt salinity BW, and also separately in FW in parallel. For the corresponding reversal of salinity, BW

Background: Anopheles stephensi, the major vector of urban malaria in India, was recently detected for the first time in Sri Lanka in Mannar Island on the northwestern coast. Since there are different biotypes of An. stephensi with different vector capacities in India, a study was undertaken to further characterise the genotype and biotype of An. stephensi in Mannar Island.

The present study was designed to assess the physico-chemical status of the pond “Ariyakulam”, to compare its status with surface water quality standards and quantify the impacts of these parameters on each other through the regression and correlation coefficient methods. Eleven selected parameters such as Air Temperature (AT), Water Temperature (WT),  Dissolved Oxygen (DO), Total Dissolved Solid (TDS), Electrical Conductivity (EC), Salinity, pH, Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Nitrate nitrogen (NO3-),Ammonia nitrogen (NH4+) were taken for the analyses. Though the pond covers approximately an area of 12,000 m2 located in a historical place, proper maintenance is lacking and the preservation of the beauty of this water body is largely neglected. Water samples were collected twice a month for a period of 8 months from August 2016 to January 2017 and then January to February, 2018 from 0700 to 0800 hrs in eight locations within the pond. The values of TDS,...

The Russell's viper (Daboia russelii) is a medically important viper found in South Asia, including Sri Lanka. This study focused on the phylogeny of Russell's vipers in the geographically segregated coastal peninsula of Jaffna, Sri Lanka. The study aimed to find out whether the specimens collected in Jaffna are different from previously reported forms since such an investigation has not been carried out so far specifically in this area, and to find out whether geographical segregation has had an impact on it. We obtained mtDNA sequences of samples representing six geographical locations in the Jaffna peninsula for the mitochondrial protein-coding genes Cytb(576bp) and ND2(270bp). Our molecular analyses recovered two distinct clades: D. russelii and D. siamensis. The clade of D. russelii comprises two sister lineages, Pakistan and India/Sri Lanka. The uncorrected pairwise Cytb genetic distance between the species range from 5.0 to 14.5 percent. The current study confirms a sister group relationship between the Indian/Sri Lankan lineage and the Pakistani lineage of the Russell's viper (D. russelii). Additionally, it discloses the presence of an incipient genetic divergence between Russell's viper populations in Jaffna and South India.

The Russell's viper (Daboia russelii) is a medically important viper found in South Asia, including Sri Lanka. This study focused on the phylogeny of Russell's vipers in the geographically segregated coastal peninsula of Jaffna, Sri Lanka. The study aimed to find out whether the specimens collected in Jaffna are different from previously reported forms since such an investigation has not been carried out so far specifically in this area, and to find out whether geographical segregation has had an impact on it. We obtained mtDNA sequences of samples representing six geographical locations in the Jaffna peninsula for the mitochondrial protein-coding genes Cytb(576bp) and ND2(270bp). Our molecular analyses recovered two distinct clades: D. russelii and D. siamensis. The clade of D. russelii comprises two sister lineages, Pakistan and India/Sri Lanka. The uncorrected pairwise Cytb genetic distance between the species range from 5.0 to 14.5 percent. The current study confirms a sister group relationship between the Indian/Sri Lankan lineage and the Pakistani lineage of the Russell's viper (D. russelii). Additionally, it discloses the presence of an incipient genetic divergence between Russell's viper populations in Jaffna and South India.