Unique pattern of histogenesis of the parakeratinized epithelium on lingual prominence in the domestic goose embryos (Anser anser f. domestica)

A triangular lingual prominence (LP) is a characteristic part of the tongue in Anseriformes containing adipose tissue. The parakeratinized epithelium (PEp) covers the LP. Studies aimed to describe the histogenesis of PEp during the process of the intensive formation of the LP in domestic goose during embryonic period and to determine the structural readiness to perform a protective function. The study were conducted by using LM, SEM and TEM technique. The results revealed that on day 16th the undifferentiated epithelium of LP transformed into the typical avian multilayered epithelium. Contrary to pattern of histogenesis of parakeratinized epithelium on the lingual body, on the medial and lateral areas of the elongating and bulging LP were formed epithelial furrows. Which around 20th day, on lateral areas of LP deepened up to half of epithelium, whereas on the medial area began to fade. The ultrastructure of cells lying in furrows indicated progressive apoptosis-like degeneration. On the 25th day, shallow furrows were only present on lateral areas, where bulging of LP was continued. Whereas the epithelium on medial area started cornification by the accumulation of cytokeratin fibers. Lack of the periderm during the development of the PEp of the LP indicated its endodermal origin.

Relationship between Blood Vessels and Migration of Neuroblasts in the Olfactory Neurogenic Region of the Rodent Brain

Neural precursors originating in the subventricular zone (SVZ), the largest neurogenic region of the adult brain, migrate several millimeters along a restricted migratory pathway, the rostral migratory stream (RMS), toward the olfactory bulb (OB), where they differentiate into interneurons and integrate into the local neuronal circuits. Migration of SVZ-derived neuroblasts in the adult brain differs in many aspects from that in the embryonic period. Unlike in that period, postnatally-generated neuroblasts in the SVZ are able to divide during migration along the RMS, as well as they migrate independently of radial glia. The homophilic mode of migration, i.e., using each other to move, is typical for neuroblast movement in the RMS. In addition, it has recently been demonstrated that specifically-arranged blood vessels navigate SVZ-derived neuroblasts to the OB and provide signals which promote migration. Here we review the development of vasculature in the presumptive neurogenic region of the rodent brain during the embryonic period as well as the development of the vascular scaffold guiding neuroblast migration in the postnatal period, and the significance of blood vessel reorganization during the early postnatal period for proper migration of RMS neuroblasts in adulthood.

PSIX-11 Bacterial clinical mastitis associated with abortion in dairy cows

Within the period from 20.04.2020 to 15.02.2021 the state of 2087 pregnant cows was studied to identify the connection between abortions and the occurrence of mastitis. During the study period 97 cases of clinical mastitis and 149 cases of abortion were identified. Abortions were observed in 42 out of 97 cows with registered clinical mastitis. It was found that cows that had a clinical form of mastitis during the first 45 days of pregnancy (in the embryonic period of development) subsequently had the maximum number of abortions - 27 heads or 64.28% of abortions of cows with mastitis. Among cows that had mastitis in the period of 46–150 days of pregnancy 13 cases of abortion were revealed (30.9% of abortions of cows with mastitis). Among cows that had mastitis during pregnancy for more than 150 days 2 cases of abortion were detected (4.7% of abortions of cows with mastitis). On the basis of bacteriological analysis, Staphylococcus spp., Streptococcus spp. and Enterobacteriaceae were isolated from milk of 15 aborted cows with the diagnosis of clinical mastitis. To identify species the conventional biochemical methods were applied together with the API 20 E, API Staph, API 20 Strep test (bioMerieux SA, France). In total, 18 species of pathogens were identified, including Ps. aeruginosa (n = 5), E. coli (n = 4), S. aureus (n = 1), S. saprophyticus (n = 8). Ps. aeruginosa, E. coli, S. aureus were isolated both from the organs of the reproductive system and from the milk of the cows who had had abortions after suffering from mastitis, whereas no relationship was found between the microflora of the reproductive system and the udder of the cows whose abortions are not associated with mastitis. The study was supported by the Russian Science Foundation, project No.20-16-00106

Response to Therapeutic Abortion in Lactating Dairy Cows Carrying Dead Twins during the Late Embryo/Early Fetal Period

This study examined the dose–response effect of prostaglandin F2α (PGF2α) when used to induce abortion in cows with two dead twins at pregnancy diagnosis 28–34 days post-AI (late embryonic period: LE) or at pregnancy confirmation 49–55 days post-AI (early fetal period: EF). The study population consisted of 415 cows receiving a single PGF2α dose (PG1 group: 254 LE and 161 EF cows) and 200 receiving a 1.5 × PGF2α dose (PG1.5 group: 121 LE and 79 EF cows). The induced abortion rate was significantly lower (chi-square test; p < 0.0001) in the EF (34.6%) than LE cows (88%), and was also reduced (p = 0.001) in the EF PG1 group (28%) compared with the EF PG1.5 group (48.1%). High milk production (≥45 kg) was the only factor influencing the induced abortion rate in LE cows (odds ratio 0.2; p < 0.0001), whereas the odds ratio for induced abortion of PG1.5 cows was 2.3 (p = 0.005) in EF cows. In conclusion, an increased PGF2α dose had no effect on abortion induction during the late embryonic period and its rate was inversely associated with milk production. This higher PGF2α dose did, however, offer benefits during the early fetal period.

Dependence of the duration of the embryonic period of development of the sevryuga (Acipenser stellatus Pallas, 1771) and the thorn (Acipenser nudiventris Lovetsky, 1828) on the temperature regime of wintering of producers

The temperature conditions and the results of wintering of producers, incubation of caviar of sevryuga and thorn in farms on waste warm waters are considered. The studied indicators are compared with similar data obtained when keeping producers from natural populations in the lower reaches of the Volga River. In the considered species, with a shortened and comfortable "warm" wintering (for sevryuga at 5-11, thorn – 3-15°C), an increase in the duration of incubation up to a day or more was recorded in comparison with individuals from natural populations. The temperature regulations of wintering for producers, incubation and maintenance of free embryos are proposed.

Plasticity of the dopaminergic phenotype and of locomotion in larval zebrafish induced by changes in brain excitability during the embryonic period.

Neuronal communication starts before the establishment of the synapses with forms of neuronal excitability occurring during the embryonic period, we called here Embryonic Neuronal Excitability (ENE). ENE has been shown to modulate the correct unfolding of development transcriptional programs but the global consequences for the developing organisms are not all understood. Here we monitored calcium transients as a proxy for ENE in zebrafish to assess the efficacy of transient pharmacological treatments applied by balneation during the embryonic period to modulate ENE. We also report lasting effects of 24h treatments, performed at the end of the embryonic development, on morphology and behavior of larval zebrafish. The post-mitotic differentiation of the dopaminergic phenotype is modulated by ENE in the forebrain. The plasticity of the dopaminergic specification occurs within a stable population of vMAT2 immuno-reactive cells, hence identifying an unanticipated biological marker for this reserve pool. We also report an effect of ENE on locomotion several days after the end of the treatments. In particular, the increase of ENE from 2 to 3 dpf promoted an hyperlocomotion in 6dpf zebrafish larvae which is an endophenotype for Attention Deficit with Hyperactivity Disorders and schizophrenia in zebrafish. These results provide a convenient framework to identify environmental factors that could regulate ENE and to study further the molecular mechanisms linking ENE to the neurotransmitters specification, with clinical relevance for the pathogenesis of neurodevelopmental disorders.