Expression of Osteopontin (OPN) mRNA in Bovine Ovarian Follicles and Corpora Lutea

The matricellular protein osteopontin (OPN) plays a role in various physiological processes, including angiogenesis and tissue remodelling. As these processes are essential for the maintenance of ovarian physiology, the aim of the study was to investigate the expression of OPN (mRNA) in ovarian cells and to evaluate whether it can be regulated by gonadotrophins. Using conventional RT‐PCR and real‐time PCR, we have detected and quantified OPN mRNA as well as glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) mRNA expression in bovine granulosa, theca and luteal cells. In all cells examined, both genes were found in equal amounts and no striking variations in the expression could be observed between granulosa, theca and luteal cells. Furthermore, no effect on either OPN or GAPDH mRNA expression was evident after culturing ovarian cells in the presence of gonadotrophic hormones, although the cells were still highly responsive in terms of cAMP formation. Although neither variations between different cell types nor a regulation of OPN mRNA expression by gonadotrophic hormones could be detected, the high and unambiguous mRNA expression in steroidogenic cells suggests that OPN should be added to the growing list of intraovarian factors which may be involved in ovarian physiology.     

Ovarian Follicular Dynamics in Buffalo Cows (Bubalus bubalis)

Follicular growth in Egyptian buffalo cows was monitored using genital tracts from 200 buffalo cows collected immediately after slaughter. According to the morphological appearance of the corpus luteum (CL), the corresponding oestrous cycle was divided into four stages: A (days 1–4), B (days 5–10), C (days 11–17) and D (days 18–21). Within these stages the follicular population on the ovaries was evaluated and the dominant follicle (DF) determined in all recovered ovaries. The functional status of the DF and the largest sub‐dominant follicles was examined by histological examination in 31 cases, and Radio Immunoassay (RIA) analyses for estradiol‐17β (E₂) and progesterone (P₄) was performed in the follicular fluid in 23 of the DF. The results showed that DFs changed their endocrine character within the stages of the oestrous cycle. The DFs between days 5 and 10 were functionally active (E₂‐dominant; non‐atretic) in most of the cases. Between days 11 and day 17 half of the DFs became functionally inactive (P₄‐dominant; atretic). At days 18–21 all of the DF became functionally active and non‐atretic. In the specimens that carried two large follicles one of them was regularly atretic and P₄‐dominant whereas the other was non‐atretic and E₂‐dominant. Between days 18 and 21 all ovaries examined showed at least one large follicle. These findings suggest that in most of the cases follicular dynamics occurs in two wave‐like patterns in the Egyptian buffalo cows.     

Embryonic Signals and Survival

The objective of this review is to give an overview of the signaling mechanisms between the conceptus and the mother before implantation. The interactions between the embryo and uterus are complex and essential for normal embryo development and implantation. Problems in the signaling mechanisms are thought to play a significant role in early embryonic mortality since a high rate of embryonic morality occurs during this period. This review will focus on the mechanisms involved in the development of the conceptus and the prevention of luteolysis. It is based primarily on what is known in ruminants but also refers to work in other species such as the mouse and primates.     

Impact of Buserelin Acetate or hCG Administration on the Day of First Artificial Insemination on Subsequent Luteal Profile and Conception Rate in Murrah Buffalo (Bubalus bubalis)

This study was designed to investigate the impact of buserelin acetate (BA) or human chorionic gonadotropin (hCG) administration on the day of first artificial insemination (AI) on subsequent luteal profile (diameter of corpus luteum (CL) and plasma progesterone) and conception rate in Murrah buffalo. The present experiment was carried out at two locations in 117 buffalo that were oestrus‐synchronized using cloprostenol (500 μg) administered (i.m.) 11 days apart followed by AI during standing oestrus. Based on treatment (i.m.) at the time of AI, buffalo were randomly categorized (n = 39 in each group) into control (isotonic saline solution, 5 ml), dAI‐BA (buserelin acetate, 20 μg) and dAI‐hCG (hCG, 3000 IU) group. Out of these, 14 buffalo of each group were subjected to ovarian ultrasonography on the day of oestrus to monitor the preovulatory follicle and on days 5, 12, 16 and 21 post‐ovulation to monitor CL diameter. On the day of each sonography, jugular vein blood samples were collected for the estimation of progesterone concentrations. All the buffalo (n = 117) were confirmed for pregnancy on day 40 post‐ovulation. The conception rate was better (p < 0.05) in dAI‐BA (51.3%) and dAI‐hCG (66.7%) groups as compared to their control counterparts (30.8%). Furthermore, the buffalo of dAI‐hCG group had improved (p < 0.05) luteal profile, whereas the buffalo of dAI‐BA group failed (p > 0.05) to exhibit stimulatory impact of treatment on luteal profile when compared to control group. In brief, buserelin acetate or hCG treatment on the day of first AI leads to an increase in conception rate; however, an appreciable impact on post‐ovulation luteal profile was observed only in hCG‐treated Murrah buffalo.     

Effect of organic,inorganic and slow-release urea fertilisers on CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from rice paddy fields

Vietnam is one of the world’s top two rice exporting countries. However, rice cultivation is the primary source of agriculture’s greenhouse gas (GHG) emissions in Vietnam. In particular, strategies are required to reduce GHG emissions associated with the application of organic and inorganic fertilisers. The objective of this study was to assess the effects of various combinations of biochar (BIOC), compost (COMP) and slow-release urea (SRU) on methane (CH₄) and nitrous oxide (N₂O) emissions. In total, 1170 gas samples were collected from closed gas chambers in rice paddies at Thinh Long commune and Rang Dong farm in northern Vietnam between June and October 2014. The gas samples were analysed for CH₄-C and N₂O-N fluxes using gas chromatography. The application of BIOC alone resulted in the lowest CH₄ emissions (4.8–59 mg C m^?2 h^?1) and lowest N₂O emissions (0.15–0.26 µg N m^?2 h^?1). The combined application of nitrogen–phosphorus–potassium (NPK) + COMP emitted the highest CH₄ (14–72 mg C m^?2 h^?1), while ½NPK + BIOC emitted the highest N₂O (1.03 µg N m^?2 h^?1 in the TL commune), but it was the second lowest (0.495 µg N m^?2 h^?1) in the RD farm. Green urea and orange urea reduced N₂O emissions significantly (p < 0.05) compared to white urea, but no significant differences were observed with respect to CH₄ emissions. SRU fertilisers and BIOC alone measured the lowest greenhouse gas intensity, i.e. <2.5 and 3 kg CO₂ eq. kg^?1 rice grain, respectively. Based on these results, application of fertilisers in the form of BIOC and/or orange or green urea could be a viable option to reduce both CH₄ and N₂O emissions from rice paddy soils.     

Novel tools for early detection of a global aquatic invasive,the zebra mussel Dreissena polymorpha

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Assessing the spawning season in common dentex (Dentex dentex) using microsatellites

A set of five variable microsatellite markers was used for the genetic characterization of two common dentex ( Dentex dentex ) broodstocks from an experimental hatchery and for the screening of the egg batches spawned during the complete spawn season in 2006. After parentage assignment, simulations were performed for the hatchery 1 broodstocks; the microsatellite set correctly assigned over 93% of descendants to parents when one parent was known and 80% when neither parent was known. Of the 261 eggs that the DNA was correctly amplified from, 254 were successfully assigned to a parental couple. More than one female or male took part (at the same point in time) in the spawning season. However, we observed 'dominant' individuals that produced high proportions of the descendants (unequal reproductive success) in all the sampling periods, although the contributions of these dominant individuals could change over time. This phenomenon reduces the effective breeding numbers, and could lead to inbreeding if this factor is not taken into account when the next parental generation is obtained. This factor should also be considered in aquaculture selection programmes because the dominant breeders may not be the most interesting individuals for commercial or productive schemes.     

Genetic diversity and connectivity patterns of harvested and aquacultured molluscs in estuaries from Asturias (northern Spain). Implications for management strategies

Estuaries are among the most important habitats of coastal areas. However, they are significantly affected by human activities worldwide, threatening their resources and the commercial uses depending on them. Fisheries and aquaculture are some of the main factors affecting the estuarine ecosystems today. In this work, we pursue the aims of genetically identifying the cultured and harvested oyster and razor clam species inhabiting Asturian estuaries (Eo, Ribadesella and Villaviciosa) and describing the genetic diversity and patterns of genetic connectivity between those species in these estuaries. The results revealed the almost complete dominance of the introduced Crassostrea gigas as the species that supports the oyster's production in Asturias with a striking diversity of gene pools in wild environments (Ría de Villaviciosa and Ribadesella) which significantly exceeds the diversity found in the hatcheries seeds commonly used for culturing. Moreover, we detected two different species of Ensis sp. inhabiting the Asturian estuaries: Ensis ensis inside Ría del Eo and Ensis directus, an invasive species, in Ría de Villaviciosa. Significant genetic differentiation between estuaries for the exotic oyster C. gigas and also for the native razor clam Solen marginatus were found. These results suggest Asturian estuaries are not a single management unit for some species and thus prevention must be taken for avoiding intentional or human‐mediated translocations among them. Biodiversity monitoring for discovering newcomer invasive species, measures for environmental recovery of these ecosystems and strict controls to avoid increasing of harvesting pressures are also a necessity to improve the management of these relevant ecosystems.