Studies on the state of tyrosyl residues in a ribonuclease from seminal vesicles.

In order to study the state of tyrosyl residues in a ribouuclease from bovine semina vesicles [EC 3.1.4.22, RNase Vs1] several lines of experiments were carried out. Spectrophotometric titration of RNase Vs1 indicated that two out of 8 tyrosine residues were titrated very easily and their apparent pKa values were about 9.8. Next, about 4 residues were titrated at pH up to 13.5. The remaining 2 residues were titrated time-dependently at pH 13.5. In 8 M urea, about 6 tyrosine residues were titrated with apparent pK4 values of about 11.2 and about 2 residues were titrated time-dependently at pH 13.5. Acetylation of RNase Vs1 with N-acetylimidazole was studied at pH 7.5. In aqueous solution, about 1.1-3.5 tyrosine residues were acetylated, depending on the experimental conditions, and in 8 M urea, 5.3 tyrosine residues were modified. RNase Vs1 was nitrated with tetranitromethane at pH 7.5. In aqueous solution, about 2.5 tyrosine residues were nitrated very easily; the enzymatic activity of the modified enzymes was 130-200% of that of the native enzyme. In 8 M urea, the reactivity of the tyrosine residues increased and about 4-5.5 residues were modified. The results of chemical modification and spectrophotometric titration indicated that about two tyrosine residues in RNase Vs1 were exposed to the solvent and were more reactive to various reagents, and 3-4 tyrosine residues were less reactive. The final 2 residues were not accessible to the reagent even in the presence of urea, but were titraten at pH 13.5. The solvent perturbation difference spectrum using ethylene glycol as a perturbant indicated that about 4 tyrosine residues were perturbed. When the pH of the enzyme solution was changed from 7.0 to 1.0, the change in optical density of RNase Vs1 due to denaturation blue shift was about 1,600 at 287nm. The optical density change at 287 nm of native RNase Vs1 on exposure to 8 M urea and 6 M guanidine-HCl indicated that the environments of 2-3 and 4 tyrosine residues were changed by the addition of the denaturants, urea and guanidine-HCl, respectively. In RNase Vs1 having about four nitrotyrosine residues, the two most inaccessible tyrosine residues remained resistant to titration with alkali. On adding nucleotide, nitrated RNase Vs1 gave a difference spectrum in the ultraviolet region but not in 320-460 nm region, where nitrotyrosine residues absorb light. This may indicate that tyrosine residues located relatively near the surface of the molecule are not perturbed directly by nucleotide binding.     

Spontaneous neoplasms of the seminal vesicles in aged Han:Chin hamsters (Cricetulus criseus)

Tumours of the seminal vesicles were found in 11 of 182 male Han:Chin hamsters kept in a life-span study from weaning to their natural death. Histologically they were classified as adenocarcinoma (n = 10) and hemangiosarcoma (n = 1). The histopathological features of the neoplasms are described.     

Age-related changes in A(1)-adenosine receptor-mediated bradycardia

The impact of age on functional sensitivity to A(1)-adenosine receptor activation was studied in Langendorff-perfused hearts from young (1-2 mo) and old (12-18 mo) male Wistar rats. Adenosine mediated bradycardia in young and old hearts, with sensitivity enhanced approximately 10-fold in old [negative logarithm of EC(50) (pEC(50)) = 4.56 +/- 0.11] versus young hearts (pEC(50) = 3.70 +/- 0. 09). Alternatively, the nonmetabolized A(1) agonists N(6)-cyclohexyladenosine and (R)-N(6)-phenylisopropyladenosine were equipotent in young (pEC(50) = 7.43 +/- 0.12 and 6.61 +/- 0.19, respectively) and old hearts (pEC(50) = 7.07 +/- 0.10 and 6.80 +/- 0. 11, respectively), suggesting a role for uptake and/or catabolism in age-related changes in adenosine sensitivity. In support of this suggestion, [(3)H]-adenosine uptake was approximately twofold greater in young than in old hearts (from 3-100 microM adenosine). However, although inhibition of adenosine deaminase and adenosine transport with 10 microM erythro-9-(2-hydroxy-3-nonyl)adenine hydrochloride and 10 microM S-(4-nitrobenzyl)-6-thioinosine increased adenosine sensitivity three- to fourfold, it failed to abolish the sensitivity difference in old (pEC(50) = 4.95 +/- 0.08) versus young (pEC(50) = 4.29 +/- 0.13) hearts. Data indicate that 1) age increases functional A(1) receptor sensitivity to adenosine without altering the sensitivity of the A(1) receptor itself, and 2) age impairs adenosine transport and/or catabolism, but this does not explain differing functional sensitivity to adenosine. This increased functional sensitivity to adenosine may have physiological significance in the older heart.     

Synthesis of seminal ribonuclease in isolated lobules of bull seminal vesicles

A procedure is described for preparing and maintaining in culture isolated lobules of bovine seminal vesicles, consisting of glandular acini, surrounded by little connective tissue and with free access to the external medium, in which secreted material can be collected. After 48 h in culture, the isolated lobules appeared indistinguishable, by morphological and biochemical criteria, from freshly isolated lobules. After much longer culture times about one third of the glandular cells were still capable of effective protein synthesis. Studying the biosynthesis of seminal ribonuclease with preparations of isolated lobules we found that the enzyme was synthesized and secreted; only the fully amidated isoenzyme was synthesized and secreted, indicating that production of the selectively deamidated isoenzymic forms occurred after secretion, newly synthesized protein was rapidly exported, indicating that the high levels of enzyme previously reported for the seminal vesicle tissue were essentially due to its content of stored secretion.     

Seminalplasmin, the major basic protein of bull seminal plasma, is a secretory protein of the seminal vesicles.

From the experimental results of three independent methods: (1) indirect immunofluorescence employing monospecific anti-seminalplasmin-IgGs, (2) cell-free translation of poly(A)+ RNA from seminal vesicle and testicular tissue, as well as (3) Northern analysis of poly(A)+ RNA of the latter tissues with a synthetic seminalplasmin-specific antisense DNA probe, it is concluded that the biosynthesis of seminalplasmin occurs in seminal vesicles but not in testis.     

Age-related changes in foraging in the German cockroach (Dictyoptera: Blattellidae)

The dynamics of exploitation of standard experimental food sources by the German cockroach, Blattella germanicaL. (Blattellidae), were analyzed in an urban habitat in relation to developmental stage. The data presented here stress differences in foraging capacities between small (first-and second-instar) larvae and animals of other developmental stages. The first animals to arrive in a food patch presented a developmental-stage distribution significantly different from that of the general population. Adults and large larvae (fifth and sixth instars) were the first to find food sources and, in particular, before small larvae. Significant differences appeared between developmental stages concerning givingup time and the time animals left a patch. Small larvae were significantly underrepresented in a patch just before food exhaustion but they were significantly more numerous than expected just after depletion. Small larvae remained in the vicinity of a depleted food dish longer than animals of other developmental stages. Adults left patches as soon as these were depleted, long before small larvae did. Developmental stage influenced rate of departure. These observations indicate that cockroaches improve their foraging performance as they grow larger.     

Spatial and seasonal changes in the diet of Oligosarcus hepsetus (Characiformes, Characidae) in a Brazilian reservoir.

We assessed spatial and seasonal changes in the diet of Oligosarcus hepsetus in order to describe the strategy developed by this species that allows their very high abundance in Lajes reservoir, Rio de Janeiro, Brazil. Fish samplings were carried out using gill nets, deployed during ca. 12 and 24 hours, between April 2001 and May 2002. A total of 289 individuals were examined, of which 97 showed gut contents. We used the index of relative importance (IRI) to compare probable dietary shifts, and the frequency of occurrence (% OC) to analyze possible ontogenetic influences on feeding. O. hepsetus showed carnivorous habits, feeding preferably on fish and insects, the latter of which occurred in 71.0% of the guts presenting contents. O. hepsetus consumed different items along the three reservoir zones: insects (61.0% IRI) and Cichla monoculus (38.9% IRI) in the lower zone; Lepidoptera (57.0% IRI) in the middle zone; and C. monoculus (77.0% IRI) in the upper zone. Food items changed seasonally with C. nonloculus predominating in autumn 2001, and Hymenoptera and Lepidoptera in the winter. In spring almost all food was Lepidoptera (99.8% IRI), while in the summer Hemiptera dominated in the diet. In autumn 2002 Hemiptera (97.0% IRI) was dominant, in significant contrast with the previous autumn. Individuals smaller than 190 mm SL fed heavily on insects, while fishes predominated in the diet of individuals larger than 190 mm SL. Shifts in prey-capture ability among length classes suggest decreasing intraspecific competition. A higher food plasticity seems to be the strategy employed by this opportunist species, which used food resources available in the reservoir.     

Cells from the seminal vesicles: contaminants of the V-C-E smear.

Cells originating in the seminal vesicles are occasionally observed on routing gynecologic smears. Sometimes, these cells may display large hyperchromatic dense nuclei, which conceivably may produce diagnostic problems. The identification of these cells is therefore of practical significance in order to avoid one more pitfall in gynecologic cytodiagnosis.     

Low levels of taurine introgression in the current Brazilian Nelore and Gir indicine cattle populations

Background

Nelore and Gir are the two most important indicine cattle breeds for production of beef and milk in Brazil. Historical records state that these breeds were introduced in Brazil from the Indian subcontinent, crossed to local taurine cattle in order to quickly increase the population size, and then backcrossed to the original breeds to recover indicine adaptive and productive traits. Previous investigations based on sparse DNA markers detected taurine admixture in these breeds. High-density genome-wide analyses can provide high-resolution information on the genetic composition of current Nelore and Gir populations, estimate more precisely the levels and nature of taurine introgression, and shed light on their history and the strategies that were used to expand these breeds.

Results

We used the high-density Illumina BovineHD BeadChip with more than 777 K single nucleotide polymorphisms (SNPs) that were reduced to 697 115 after quality control filtering to investigate the structure of Nelore and Gir populations and seven other worldwide populations for comparison. Multidimensional scaling and model-based ancestry estimation clearly separated the indicine, European taurine and African taurine ancestries. The average level of taurine introgression in the autosomal genome of Nelore and Gir breeds was less than 1% but was 9% for the Brahman breed. Analyses based on the mitochondrial SNPs present in the Illumina BovineHD BeadChip did not clearly differentiate taurine and indicine haplotype groupings.

Conclusions

The low level of taurine ancestry observed for both Nelore and Gir breeds confirms the historical records of crossbreeding and supports a strong directional selection against taurine haplotypes via backcrossing. Random sampling in production herds across the country and subsequent genotyping would be useful for a more complete view of the admixture levels in the commercial Nelore and Gir populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-015-0109-5) contains supplementary material, which is available to authorized users.     

Expression of opioid genes in bovine seminal vesicles

In seminal vesicles, the organ producing most of seminal plasma in the bovine species, the pro-opiomelanocortin and the proenkephalin genes are transcribed and translated, and their translation products processed into opioid peptides, which are secreted into the seminal plasma. By using a micro-organ preparation of seminal vesicles we found that, after 20 h of incubation with labelled methionine, a multiplicity of opioids was produced. Among these, [Met]enkephalin and beta-endorphin were positively identified, whereas in the newly formed secretion only [Met]enkephalin was detected. This may be correlated to the finding that the concentration of beta-endorphin in an extract of seminal plasma was one order of magnitude lower than that of [Leu]enkephalin and [Met]enkephalin. These findings expand the picture of the presence of opioid peptides in the male reproductive tract, indicating that they should have a role(s) in the physiology of reproduction, not only in the hypothalamus-pituitary-gonadal axis, determining the reproductive potential, but also in the so-termed sex accessory glands, determining the actual events leading to reproduction. To our knowledge this is also the first case studied of opioid peptides produced as exocrine hormones.     

Effects on long-term cadmium exposure on the seminal vesicles of mice.

Male CBA-mice were exposed to cadmium by subcutaneous injection of 2-2 mumol CdCl2/kg body weight for 5 days/week for 6 months. A decrease in normal (testosterone-dependent) proteinuria was shown, and morphological examination of the seminal vesicles revealed a smaller weight and size as well as histological indication of lower secretory activity of the epithelium compared to controls. The findings are consistent with a theory implying a decreased testosterone activity in cadmium-treated animals.