Effective Synthesis and Antifouling Activity of Dolastatin 16 Derivatives

Some derivatives of dolastatin 16, a depsipeptide natural product first obtained from the sea hare Dolabella auricularia, were synthesized through second-generation synthesis of two unusual amino acids, dolaphenvaline and dolamethylleuine. The second-generation synthesis enabled derivatizations such as functionalization of the aromatic ring in dolaphenvaline. The derivatives of fragments and whole structures were evaluated for antifouling activity against the cypris larvae of Amphibalanus amphitrite. Small fragments inhibited the settlement of the cypris larvae at potent to moderate concentrations (EC₅₀ = 0.60-4.62 μg/mL), although dolastatin 16 with a substituent on the aromatic ring (24) was much less potent than dolastatin 16.     

Microenvironmental characteristics of intestinal biocenosis in calves with syndrome of hypotrophy

Disorders of normal intestinal biocenosis formation, decline in colonization resistance, and more pronounced effect of predisposition to gastrointestinal diseases in hypotrophic calves were ascertained.     

Population structure of the fish pathogen Flavobacterium psychrophilum at whole-country and model river levels in Japan

The bacterium Flavobacterium psychrophilum is a serious problem for salmonid farming worldwide. This study investigates by multilocus sequence typing (MLST) the population structure of this pathogen in Japan where it is also a major concern for ayu, a popular game fish related to salmoniforms. A total of 34 isolates collected across the country and 80 isolates sampled in a single model river by electrofishing were genotyped. The data accounting for 15 fish species allowed identifying 35 distinct sequence types (ST) in Japan. These ST are distinct from those reported elsewhere, except for some ST found in rainbow trout and coho salmon, two fish that have been the subject of intensive international trade. The pattern of polymorphism is, however, strikingly similar across geographical scales (model river, Japan, world) in terms of the fraction of molecular variance linked to the fish host (~50%) and of pairwise nucleotide diversity between ST (~5 Kbp^-1). These observations go against the hypothesis of a recent introduction of F. psychrophilum in Japan. Two findings were made that are important for disease control: 1) at least two independent F. psychrophilum lineages infect ayu and 2) co-infections of the same individual fish by different strains occur.     

Exploration of factors determining milk production by Holstein cows raised on a dairy farm in a temperate climate area

In this study, we examined factors that affected milk production by cows raised in a temperate climate area. We conducted this study on a large dairy farm containing approximately 2000 Holstein cows, located in a temperate climate area. We collected 7803 calving records for 4069 cows from 2012 to 2016. We then assessed the effect of hot weather on milk yield by examining three climate factors: season, maximum temperature (MAX), and the temperature and humidity index (THI). We found that increases in heat stress caused linear decreases in milk yield (P?<?0.05). Additionally, the effects of the three climate factors on milk yield varied depending on cow parity and days open (P?<?0.05). Thus, management procedures should consider cow parity and lactating stage to minimize the negative effects of heat stress on milk production. We also found that the lowest Akaike information criterion value was obtained in our model when using THI for 305-day milk yield. This suggests that THI is a more accurate variable for evaluating heat stress than MAX or season.

     

Genetic diversity and population structure in Jatropha (Jatropha curcas L.) based on molecular markers

Genetic Resources and Crop Evolution - Jatropha (Jatropha curcas L.) is an oleaginous potential, howetever, some studies report that there is low genetic diversity in Brazilian genotypes....     

Cytogenetics Analysis and Testis Morphology of Aquatic Species of the Families Belostomatidae,Gelastocoridae, Gerridae,Notonectidae, and Veliidae (Heteroptera)

The Heteroptera have holocentric chromosomes with kinetic activity restricted to the end of chromosomes. The first meiotic division is reductional for the autosomes and equational for the sexual. Only a few species of this suborder have been analyzed. In this study, we observed the morphologies of the testes of the Heteroptera species Belostoma anurum (Herrich-Schäffer, 1948), Belostoma micantulum (Stal, 1858), Gelastocoris angulatus (Melin, 1929), Gelastocoris flavus flavus (Guérin-Méneville, 1844), Rheumatobates crassifemur crassifemur (Esaki, 1926), Buenoa amnigenus (White, 1879), Buenoa unguis (Truxal, 1953), Martarega brasiliensis (Truxal, 1949), Martarega membranácea (White, 1879), Martarega uruguayensis (Berg, 1883), Rhagovelia tenuipes (Champion, 1898) and Rhagovelia zela (Drake, 1959). We found that the testes of these species can be round, round/spiral, or elongated/spiral. The size of the prophase I cells was found to vary, with the smallest ones being detected in B. micantulum and Rha. zela, the largest in G. f. flavus, and ones of intermediate size in R. c. crassifemur and M. brasiliensis. With respect to the chromosome complement, we verified the presence of 2n = 16 (14A+XY, B. micantulum and G. angulatus), 21 (20A+X0, R. c. crassifemur), 23 (22A+X0, Rha. zela and Rha. tenuipes), 25 (24A+X0, Bu. amnigenus and Bu. unguis; 22A+2m+X0, M. membranacea), 27 (24A+2m+X0, M. brasiliensis and M. uruguayensis), 29 (26A+X₁X₂Y, B. anurum), and 35 (30A+X₁X₂X₃X₄Y, G. f. flavus). We found that the features of spermatogenesis in these species are similar to those of other previously described Heteroptera species, differing only in testicular morphology, chromosome number, and sex chromosome system.     

Demonstration of the absence of intervening sequences (IVSs) within 16S rRNA genes of Taylorella equigenitalis and Taylorella asinigenitalis isolates

A total of 57 Taylorella equigenitalis (n=22) and Taylorella asinigenitalis (n=35) isolates was shown not to carry any intervening sequences (IVSs) within 16S rRNA gene sequences. By contrast, we have already shown the genus Taylorella group to carry several kinds of IVSs within the 23S rRNA gene sequences.     

Effect of methimazole-induced hypothyroidism on adrenal and gonadal functions in male Japanese quail (Coturnix japonica)

To investigate the effect of hypothyroidism on gonadal and adrenal functions in male Japanese quail (Coturnix japonica), hypothyroidism was induced in male adult Japanese quail by daily administration of 2-Mercapto-1-methylimidazole (methimazole) in their drinking water. Four weeks after methimazole treatment, the Japanese quail were sacrificed, and the plasma concentrations of free triiodothyronine (FT3), free thyroxine (FT4), total T3 (TT3), total T4 (TT4), corticosterone, testosterone, LH and immunoreactive (ir) inhibins were measured by radioimmunoassay, the testes and adrenal glands were removed and weighed and the thyroid glands and testes were fixed in 4% paraformaldehyde for histological observation. The results showed that the hypothyroidism induced by methimazole caused a significant decrease in body and testes weight; the plasma levels of FT3, FT4 and TT4 significantly decreased, and the hypothyroid quail possessed a greater number of small follicles and more follicular epithelial cells in the thyroid gland. In addition, hypothyroidism resulted in a significant decrease in the plasma concentrations of corticosterone, LH, testosterone and ir-inhibin. Furthermore, no spermatogenesis was found in the seminiferous tubules of the methimazole treatment groups. These results clearly demonstrate that hypothyroidism caused both gonadal and adrenal disturbances in the adult male Japanese quail.     

Relationships between immunoglobulin and fat‐soluble vitamins in colostrum of Japanese Black multiparous cows

Data from 19 Japanese Black multiparous cows were collected to clarify the relationships among immunoglobulin (Ig) G, IgA, β‐carotene, vitamin A and α‐tocopherol contents in colostrum of cows in order to evaluate the role of fat‐soluble vitamins on colostral IgG and IgA production. Mean colostral IgG was 141 mg/mL, ranging from 65 to 208 mg/mL, whereas mean colostral IgA was 8.7 mg/mL, ranging from 1.0 to 34.6 mg/mL. Colostral IgG increased with aging in multiparous cows. There were positive correlations between colostral IgG and colostral vitamin A or colostral α‐tocopherol in cows, and the higher adjusted R² was obtained in the prediction model of colostral IgG from age and colostral vitamin A. Colostral vitamin A was positively correlated with colostral β‐carotene or colostral α‐tocopherol in cows, but there were no relationships between colostral IgA and colostral IgG or colostral fat‐soluble vitamins. These results indicate that fat‐soluble vitamin contents in colostrum of cows may change in similar patterns and high colostral vitamin A is related with high colostral IgG.     

Structure and genetic diversity of macauba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] approached by SNP markers to assist breeding strategies

Genetic Resources and Crop Evolution - Macauba palm [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] is a perennial oil, it stands out for having several characteristics of commercial interest, mainly...