Search

The Malabar dwarf puffer, Carinotetraodon travancoricus is the smallest known pufferfish (family Tetraodontidae) and one of the smallest freshwater fishes of the Indian subcontinent. Due to their miniature size, wacky behaviour and appearance, they are much preferred in the international aquarium fish trade, although little is known regarding their breeding activity in captivity and their embryonic development. The purpose of this study was to fill these knowledge gaps. Wild-caught Malabar dwarf puffers were acclimatised to conditions, and pairs were introduced to breeding tanks. Adult fishes were fed with live and frozen diets including Artemia nauplii, moina and bloodworm. During spawning seasons, adult fish displayed elaborate courtship behaviour around sunset. Carinotetraodon travancoricus is a batch spawner releasing 1 to 5 eggs per diem. The eggs were spherical, and non-sticky, with a diameter of 1.48 ± 0.1 mm, and hatching took place after 108 to 116 h post-incubation. The newly hatched larvae were 3.5 ± 0.2 mm in length, and weighed 2.9 ± 0.4 mg. The early larvae have substantial yolk and oil globules as an energy reserve. Histological studies on mature females suggested the batch spawning nature of the species and low fecundity. Given its unique reproductive behaviour and characters, in situ protected habitats are required to ensure their continued survival in the wild, apart from encouraging captive breeding to augment the demand in the international aquarium fish trade.

Summary: Garra gotyla is an indigenous coldwater fish of the cyprinid family and has wide geographical distribution in India as well as in other countries of Asia and Africa. Induced breeding in G. gotyla was carried out successfully for the first time and an attempt has been made to document developmental stages chronologically from the first minute of fertilization, through all stages of embryonic development until the fifth day post hatching. This experiment was carried out at 22–24°C water temperature at the Directorate of Coldwater Fisheries Research, Bhimtal, India. During the breeding trial, the fertilization rate was observed as 70–75% and hatching rate was 85–90%. The mature fertilized ova were measured as 0.8–1.0 mm in diameter and the perivitelline membrane became thick soon after fertilization and formation of the germ pole. The periods taken for complete developmental stages were recorded; cleavage stage 111 min (min post fertilization (pf)), blastulation stage 580 min (pf), neurulation and segmentation 1250 min (pf) and hatching was completed after 1420 min. The sac fry was measured as 3 mm in length and took almost 3 days for complete absorption of the yolk content. The major structural and differential changes observed are in head, tail, fins, alimentary canal, rudiments of each organ and appearance of melanophore pigmentation in the whole body. The 5-day-old larvae were measured as 6 mm in length with almost every organ fully differentiated. The present study will be utilized for large-scale production of fingerlings for stock enhancement in rivers, lakes and possibilities of genetic improvement and manipulation at the embryonic stage. [ABSTRACT FROM AUTHOR]

The study describes, for the first time, captive breeding, embryonic and larval development of Barilius bendelisis. The captive breeding trial was carried out in April, in fish farm of Directorate of Coldwater Fisheries Research (DCFR), Bhimtal, India using differnet doses of ovatide. The most appropriate dose of ovatide was reported to be 0.3 ml/kg body weight to males and 0.6 ml/kg body weight to females. Fertilized eggs measuring 1.4-1.7 mm were spherical, demersal, and transparent with dark yellow coloured yolk. Hatching occurred 140 -160 hours after fertilization at 19.09℃ ± 0.395. Newly hatched larvae were transparent with yellowish yolk reserve, measuring 5.57 - 6.71 mm in total length and characterized by pigmented eye and yolk sac which completely absorbed in 72 hours. [ABSTRACT FROM AUTHOR]

Abstract: The unusual feature of the breeding cycle of Cynopterus sphinx at Varanasi is the significant variation in gestation length of the two successive pregnancies of the year. The aim of this study was to investigate whether the prolongation of the first pregnancy in C. sphinx is due to delayed embryonic development. The first (winter) pregnancy commences in late October and lasts until late March and has a gestation period of about 150 days. The second (summer) pregnancy commences in April and lasts until the end of July or early August with a gestation period of about 125 days. Changes in the size and weight of uterine cornua during the two successive pregnancies suggest retarded embryonic growth during November and December. Histological analysis during the period of retarded embryonic development in November and December showed a slow gastrulation process. The process of amniogenesis was particularly slow. When the embryos attained the early primitive streak stage, their developmental rate suddenly increased considerably. During the summer pregnancy, on the other hand, the process of gastrulation was much faster and proceeded quickly. A comparison of the pattern of embryonic development for 4 consecutive years consistently showed retarded or delayed embryonic development during November and December. The time of parturition and post-partum oestrus showed only a limited variation from 1 year to another. This suggests that delayed embryonic development in C. sphinx may function to synchronize parturition among females. The period of delayed embryonic development in this species clearly coincides with the period of fat deposition. The significance of this correlation warrants further investigation. [Copyright &y& Elsevier]

Polyunsaturated fatty acids (PUFAs) play multiple physiological roles. They regulate the structure and function of cell membranes and cell growth and proliferation, and apoptosis. In addition, PUFAs are involved in cellular signaling, gene expression and serve as precursors to second messengers such as eicosanoids, docosanoids etc. and regulate several physiological processes including placentation, inflammation, immunity, angiogenesis, platelet function, synaptic plasticity, neurogenesis, bone formation, energy homeostasis, pain sensitivity, stress, and cognitive functions. Linoleic acid, 18:2n-6 (LA) and alpha-linolenic acid, 18:3n-3 (ALA) are the two essential fatty acids obtained from the diets and subsequently their long-chain polyunsaturated fatty acids (LCPUFAs) are accumulated in the body. The maternal plasma LCPUFAs especially accumulated in larger amounts in the brain during the third trimester of pregnancy via the placenta and postnatally from mother's breast milk. Various studies, including ours, suggest PUFA's important role in placentation, as well as in growth and development of the offspring. However, intakes of maternal n-3 PUFAs during pregnancy and lactation are much lower in India compared with the Western population. In India, n-3 fatty acid status is further reduced by higher intake of n-6 PUFA rich oils and trans fats. More data on the impacts of long term maternal n-3 PUFA deficiency on placental structure and function, gene expression, epigenetic changes and resultant cognitive function of fetus & infants are emerging. This review summarizes the impacts of n-3 PUFA deficiency in utero on fetal growth and development, adiposity, energy metabolism, musculoskeletal development, and epigenetic changes in feto-placental axis from the recently available pre-clinical and clinical data., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Historically, research in India on early mammalian development had only begun, rather modestly, in the last century, unlike the USA and UK. In India, initial studies were on gonadal and reproductive tissue development and function and they were limited to anatomical and histological characterization. This was followed by research on fertility regulation and contraception. Since the 1960s, a major initiative took place regarding endocrine biochemistry and the use of antifertility agents in inhibiting gonadal function and early development. Post-independence, the Indian government´s funding support enabled universities and institutions to embark on various research disciplines in biology but with no particular emphasis on developmental biology per se. Subsequently, India made significant progress in the area of mammalian reproduction and development, but not specifically in the core aspects of developmental biology. Reasons for this could be due to the nation's compulsion to invest and embark on socio-economic and infrastructure development and on research involving family planning methods for reversible-affordable contraceptives to curtail population growth. With regard to the latter, biologists were involved in hormone-based contraception research. During this pursuit, insights were achieved into basic aspects of the development of gonads, gametes and embryos. Notwithstanding this, in the post-1980s through to the present time, Indian scientists have contributed to (i) the understanding of the cellular and molecular regulation of early development, (ii) developing genetically modified mouse models, (iii) using assisted reproductive technologies, generating mammalian progeny, including humans and (iv) deriving pluripotent stem cell lines for developmental studies. This article provides a perspective on the past and current status of early mammalian development research in India.

This issue of The International Journal of Developmental Biology (Int. J. Dev. Biol.) is devoted to contributions to developmental biology from India. The articles have been organized thematically, beginning with historical accounts and personal reminiscences, followed by surveys of areas to which the authors' own contributions have been substantial, and ending with reports of original research. The articles selected for the 'history' section are by those who have witnessed events from close quarters, and in most cases have contributed to the work in question. The range of articles is vast but cannot claim to be comprehensive. Some areas may have been left out inadvertently, either because we were unable to find anyone to cover them, or maybe in part because of not looking in the right place. Other areas are missed out because, much to our regret, authors did not deliver promised manuscripts on time. In short, the Special Issue is indicative of what went on and is going on in the field of developmental biology in India, but it does have gaps.

In June 2018, I traveled to India to teach in a Tibetan Buddhist monastery under the auspices of the Emory-Tibet Science Initiative (ETSI), a program that brings aspects of science education to the three major Tibetan monastic universities in exile. My role was to teach developmental biology to the monks over a 9-day period, and I found zebrafish development to be an excellent vehicle for introducing them to both the wonder of embryonic development and to some of the most advanced findings in the field of developmental biology. I describe here my experiences, observations, and thoughts about how the monastic system will need to change if the monks are really to develop the ability to think like scientists.

The availability of techniques for the vitrification of cloned blastocysts can improve their effective use. The present study compared the developmental competence of buffalo cloned embryos derived from adult (BAF), newborn (BNF) and fetal fibroblast (BFF) before and after vitrification. Despite similar cleavage rates among the three groups, the blastocyst rate was lower for BAF- than BNF- and BFF-derived embryos (30.2±2.2% vs 41.7±1.7% and 39.1±2.1%, respectively; P<0.01). The total cell number of BNF-derived blastocysts was significantly higher (P<0.01) than that of BFF-derived blastocysts, which, in turn, was higher (P<0.01) than that of BAF-derived blastocysts. Following transfer of vitrified-warmed blastocysts to recipients, no pregnancy was obtained with fresh (n=8) or vitrified-warmed (n=18) BAF-derived blastocysts, whereas transfer of fresh BNF- (n=53) and BFF-derived (n=32) blastocysts resulted in four and three pregnancies, respectively, which aborted within 90 days of gestation. The transfer of vitrified-warmed BNF-derived blastocysts (n=39) resulted in the live birth of a calf weighing 41kg, which is now 23 months old and has no apparent abnormality, whereas the transfer of vitrified-warmed BFF-derived blastocysts (n=18) resulted in one live birth of a calf that died within 6h. These results demonstrate that cloned buffalo embryos cryopreserved by vitrification can be used to obtain live offspring.

Healthy individuals of matured clownfish, Amphiprion nigripes and sea anemone, Heteractis magnifica were collected from the Agatti island lagoon by snorkeling. During 'conditioning' for 3 months, pair formation occurred and the same were transferred to rectangular fiber glass spawning tanks of 10001 capacity. Suitable water quality parameters were maintained. The fishes were fed with tuna eggs, boiled clam meat, squid, octopus and trash fish thrice in a day. Reproductive behaviour and embryonic development were documented. Spawning took place in between 0900 - 1100 hr and hatched-out occurs, after sunset following an incubation period of 8-9 days. Size of the newly laid egg was 2.0-2.2 mm in length and 1.0-1.2 mm in width. The larval rearing tanks were maintained with UV-treated water and followed the optimal physico-chemical parameters as in the parent tanks. The different light regimes and diets were used for the successful larval rearing. The maximum larval survival (61%) was achieved at the photoperiod of 24 L/0D. Within 15-17 days, the larvae metamorphosed and took up parent colouration and comparatively high growth rate was observed when fed on algae enriched rotifer than those with poly unsaturated fatty acid (PUFA).

We describe our experience with the use of embryo biopsy and fluorescent in-situ hybridization (FISH) in order to sex embryos for the purpose of family balancing in a private IVF clinic in India from April 1999-April 2001. Embryos were biopsied and analysed on day 3, cultured in sequential media, and then transferred on day 4 or day 5 after morphological selection of the best embryos. From a total of 42 cycles started, we achieved 14 clinical pregnancies and have had nine live births so far with five ongoing pregnancies. This is the first report of the use of preimplantation sex selection for family balancing in India, where couples place a premium on having baby boys, and the social and ethical aspects of the use of this technology in this setting are discussed.