Revelation of candidate genes and molecular mechanism of reproductive seasonality in female rohu (Labeo rohita Ham.) by RNA sequencing.

BACKGROUND: Carp fish, rohu (Labeo rohita Ham.) is important freshwater aquaculture species of South-East Asia having seasonal reproductive rhythm. There is no holistic study at transcriptome level revealing key candidate genes involved in such circannual rhythm regulated by biological clock genes (BCGs). Seasonality manifestation has two contrasting phases of reproduction, i.e., post-spawning resting and initiation of gonadal activity appropriate for revealing the associated candidate genes. It can be deciphered by RNA sequencing of tissues involved in BPGL (Brain-Pituitary-Gonad-Liver) axis controlling seasonality. How far such BCGs of this fish are evolutionarily conserved across different phyla is unknown. Such study can be of further use to enhance fish productivity as seasonality restricts seed production beyond monsoon season. RESULT: A total of ~ 150 Gb of transcriptomic data of four tissues viz., BPGL were generated using Illumina TruSeq. De-novo assembled BPGL tissues revealed 75,554 differentially expressed transcripts, 115,534 SSRs, 65,584 SNPs, 514 pathways, 5379 transcription factors, 187 mature miRNA which regulates candidate genes represented by 1576 differentially expressed transcripts are available in the form of web-genomic resources. Findings were validated by qPCR. This is the first report in carp fish having 32 BCGs, found widely conserved in fish, amphibian, reptile, birds, prototheria, marsupials and placental mammals. This is due to universal mechanism of rhythmicity in response to environment and earth rotation having adaptive and reproductive significance. CONCLUSION: This study elucidates evolutionary conserved mechanism of photo-periodism sensing, neuroendocrine secretion, metabolism and yolk synthesis in liver, gonadal maturation, muscular growth with sensory and auditory perception in this fish. Study reveals fish as a good model for research on biological clock besides its relevance in reproductive efficiency enhancement.

TRPA1 is selected as a semi-conserved channel during vertebrate evolution due to its involvement in spermatogenesis.

TRPA1 is a non-selective cation channel originated in invertebrates. The genomic locus containing TRPA1 gene remains highly conserved and retained in all vertebrates. TRPA1 gene is evolutionarily selected, yet maintained as a highly diverged protein. Throughout the vertebrate evolution, the extracellular loops of TRPA1 become most diverged indicating that TRPA1 may be involved in detecting large spectrum and uncertain stimulus which is critical for adaptive benefit. We tested the expression of TRPA1 in mature sperm from different vertebrates. This is the first report demonstrating that TRPA1 is expressed endogenously in mature spermatozoa of multiple species representing entire vertebrate phyla. However, its specific localization within sperm remains species-specific. Accordingly, we report that in rodents TRPA1 expression correlates with different stages of spermatogenesis. We propose that presence of endogenous TRPA1 in testes and in mature sperm provides reproductive benefit.

Construction, De-Novo Assembly and Analysis of Transcriptome for Identification of Reproduction-Related Genes and Pathways from Rohu, Labeo rohita (Hamilton).

Rohu is a leading candidate species for freshwater aquaculture in South-East Asia. Unlike common carp the monsoon breeding habit of rohu restricts its seed production beyond season indicating strong genetic control over spawning. Genetic information is limited in this regard. The problem is exacerbated by the lack of genomic-resources. We identified 182 reproduction-related genes previously by Sanger-sequencing which were less to address the issue of seasonal spawning behaviour of this important carp. Therefore, the present work was taken up to generate transcriptome profile by mRNAseq. 16 GB, 72 bp paired end (PE) data was generated from the pooled-RNA of twelve-tissues from pre-spawning rohu using IlluminaGA-II-platform. There were 64.97 million high-quality reads producing 62,283 contigs and 88,612 numbers of transcripts using velvet and oases programs, respectively. Gene ontology annotation identified 940 reproduction-related genes consisting of 184 mainly associated with reproduction, 223 related to hormone-activity and receptor-binding, 178 receptor-activity and 355 embryonic-development related-proteins. The important reproduction-relevant pathways found in KEGG analysis were GnRH-signaling, oocyte-meiosis, steroid-biosynthesis, steroid-hormone biosynthesis, progesterone-mediated oocyte-maturation, retinol-metabolism, neuroactive-ligand-receptor interaction, neurotrophin-signaling and photo-transduction. Twenty nine simple sequence repeat containing sequences were also found out of which 12 repeat loci were polymorphic with mean expected-&-observed heterozygosity of 0.471 and 0.983 respectively. Quantitative RT-PCR analyses of 13-known and 6-unknown transcripts revealed differences in expression level between preparatory and post-spawning phase. These transcriptomic sequences have significantly increased the genetic-&-genomic resources for reproduction-research in Labeo rohita.

Factors affecting the uptake of DMSO by the eggs and embryos of medaka, Oryzias latipes.

High performance liquid chromatography (HPLC) was used to assess the uptake dynamics of the cryoprotectant DMSO by intact unfertilized eggs (stage 0), 8-cell (stage 5) and eyed embryos (stage 30) of medaka, Oryzias latipes, the relation of the internal concentration (Cin) of DMSO with fertilization and survival rates, and the effects of several factors on these processes. The factors examined were: cryoprotectant concentration (0.6, 1.2, 1.9 and 2.5 M), impregnation time (1, 3, 5, 10, 15 and 20 min), temperature (0, 5 and 20 degrees C), hydrostatic pressure (0 and 50 atm), and the osmotic conditions of the materials (normal or partially dehydrated). Cryoprotectant permeation, estimated from the initial rates of DMSO uptake, was higher in embryos than in eggs and increased with embryonic development; however, the DMSO Cin in eyed embryos reached a plateau at 1-5 min and could not be increased by prolonging impregnation. The highest fertilization and survival rates for any given DMSO Cin were obtained with high concentrations and short times of impregnation rather than low concentrations and long impregnation times. Application of hydrostatic pressure (50 atm) and exposure for 3 min to a 1 M trehalose solution prior to impregnation induced a substantial increase in the DMSO Cin of 8-cell embryos in comparison to untreated controls with no significant effect on survival. Hydrostatic pressure also promoted DMSO uptake in unfertilized eggs, but with rapid loss of viability, and was ineffective in eyed embryos. The uptake of DMSO and its toxicity to 8-cell embryos were directly proportional to the temperature of impregnation. The results of this study reveal important interactions between cryoprotectant concentration, impregnation time and the developmental stage (or type) of the materials and provide evidence that hydrostatic pressure, temperature of impregnation and the osmotic conditions of the materials can be manipulated to increase the uptake of cryoprotectant by fish eggs and embryos.

Prevalence of abnormal spermatozoa in tobacco chewing sub-fertile males.

AIM: The aim of the following study is to find out the prevalence of abnormal spermatozoa and associated functional parameters in clinical semen samples of sub-fertile males with the tobacco chewing habit. SETTINGS AND DESIGN: Retrospective study was conducted at infertility unit of a tertiary health care center, in a period of 3 years. MATERIALS AND METHOD: Semen of 642 males were analyzed; of them 194 men (30.2%) were tobacco chewers and they were grouped according to their intensity of chewing (<10 and ≥ 10 packets/day). Counts, motility, vitality, and morphology of sperms were analyzed. RESULTS: In tobacco chewers, 66% of subjects were oligozoospermic, 85% asthenozoospermic and 28% teratozoospermic. Sperm counts (odds ratio [OR] =2.2; 95% confidence interval [CI]: 1.5-3.09), motility (OR = 3.2; 95% CI: 2.05-4.9), and normal morphology (OR = 8.4; 95% CI: 4.9-14.6) were significantly affected (P = 0.001) in tobacco chewers than the non-chewing group. Further, in comparison to the intensity of tobacco chewing, patients with the intensive practice of using ≥10 packets/day had a significant effect on sperm morphology (P = 0.003, OR = 2.7; 95% CI = 1.41-5.08) only. Structural defects in head (P = 0.001) and cytoplasmic residues (P = 0.001) were found to be positively correlated with the intensive chewing, but no significant changes were found in anomalies in mid-piece and tail. CONCLUSION: The adverse impact of tobacco chewing on semen parameters was evident even with mild chewers, but with the intensive chewing practice, phenotypes of sperms, mainly defects in the head and cytoplasmic residue were severely affected.

Targeting nonhealing ulcers of lower extremity in human through autologous bone marrow-derived mesenchymal stem cells.

Bone marrow (BM)-derived mesenchymal stem cells (MSCs) represent a promising population for supporting new concepts in cellular therapy. This study was undertaken to assess the efficacy and feasibility of autologous BM-derived MSCs in the treatment of chronic nonhealing ulcers (diabetic foot ulcers and Buerger disease) of the lower extremities. A total of 24 patients with nonhealing ulcers of the lower limb were enrolled and randomized into implant and control groups. In the implant group, the patients received autologous cultured BM-derived MSCs along with standard wound dressing; the control group received only the standard wound dressing regimen, followed up for at least a 12-week period. Wound size, pain-free walking distance, and biochemical parameters were measured before therapy and at every 2-week interval following intervention. The implant group had significant improvement in pain-free walking distance and reduction in ulcer size as compared to those in the control group. In the implant group for Buerger disease, the ulcer area decreased from 5.04 +/- 0.70 cm(2) to 1.48 +/- 0.56 cm(2) (p < 0.001), whereas the pain-free walking distance increased from 38.33 +/- 17.68 m to 284.44 +/- 212.12 m (p < 0.001). In the diabetic foot ulcer group, the ulcer size decreased from 7.26 +/- 1.41 cm(2) to 2 +/- 0.98 cm(2) (p < 0.001) at 12 weeks. Mononuclear cells were cultured for a minimum of five passages and characterized by cell-surface markers showing CD90+, CD105+, and CD34(-). There was no significant alteration in the biochemical parameters observed during the follow-up period, indicating normal liver and renal function following intervention. Biopsy microsection of implanted tissues showed development of dermal cells (mainly fibroblasts), including mature and immature inflammatory cells. The study indicates that autologous implantation of BM-derived MSCs in nonhealing ulcers accelerates the healing process and improves clinical parameters significantly.

Use of the non-toxic cryoprotectant trehalose enhances recovery and function of fish embryonic stem cells following cryogenic storage.

Fish embryonic stem (ES) cells derived from of blastulae (64 cell stage embryo) of Labeo rohita were propagated in culture and retained their ES cell-like properties after cryogenic storage (-196 degrees C, i.e., liquid nitrogen). Toxic effect of DMSO (dimethyl sulphoxide) on stem cells during preservation process has been reported to restrict therapeutic applications. In this study we reduced the concentration of DMSO and added the non-toxic cryoprotective agent (CPA) trehalose. Cryopreservation of ES cell colonies was done at 5, 25 and 52 passages with 0.2 M trehalose and 0.8 M (DMSO). A combination of both the cryoprotective agents (non-toxic and toxic) demonstrated better survival and recovery of ES cells than the DMSO used alone. Use of this CPA combination in the freezing media gave an optimum viability of more than 83 % in a slow freezing protocol. Trehalose showed a definite advantage over DMSO in terms of viability and intactness of ES cell colonies with evenly distributed morphology. There was no significant difference observed in the expression levels of cell surface markers like stage specific embryonic antigen-1 (SSEA-1) and alkaline phosphatase (ALP) between early and late passages after 60 days of post-thawing. More than 90 % of the ES cell colonies showed extensive expression of ALP and positive expression of SSEA-1 from an early stage of ES cells culture up to passage 52 (in our study) in the presence of leukemia inhibitory factor (LIF) and without feeder cells. Further, thawed ES cells showed a normal karyotype and maintained an undifferentiated state through out the study. This study on ES cell cryopreservation and subsequent retention of stem cell properties without feeder cells using a non-toxic cryoprotectant trehalose would be highly useful for future in vitro differentiation, manipulation of fish ES cells and as a model for mammalian ES cell culture.