Parasitic castration by the digenian trematode Allopodocotyle sp alters gene expression in the brain of the host mollusc Haliotis asinina

Infection of molluscs by digenean trematode parasites typically results in the repression of reproduction - the so-called parasitic castration. This is known to occur by altering the expression of a range of host neuropeptide genes. Here we analyse the expression levels of 10 members of POU, Pax, Sox and Hox transcription factor gene families, along with genes encoding FNIRFamide, prohormone convertase and P-tubulin, in the brain ganglia of actively reproducing (summer), non-reproducing (winter) and infected Haliotis asinina (a vetigastropod mollusc). A number of the regulatory genes are differentially expressed in parasitised H. asinina, but in only a few cases do expression patterns in infected animals match those occurring in animals where reproduction is normally repressed. (c) 2006 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.

Primal joints and hind-leg cuts of entire and castrated Javan Rusa (Cervus timorensis russa) stags

The effects of castration on the primal joints and the cuts of the leg joint of Javan rusa (Cervus timorensis russa) stag carcases was investigated at three slaughter ages (13, 19 and 25 months). Castration reduced the weights of some primal joints in the 19- and 25-months age groups, but not at 13 months. At 19 months, the neck, and neck plus chuck, were heavier by 35 and 17% respectively in entires (P < 0.05), and at 25 months entires had heavier carcases, shoulder, forequarter and hindquarter (P < 0.05). The leg and saddle joints were approximately 39 and 18% of the side, respectively, for both treatments and all ages. The proportions of the neck, and neck plus chuck, were higher (P < 0.05) in 19-month old entires than castrates. There were few significant differences between treatments in the weight or proportion of the hind leg cuts at any slaughter age, but in the 25-months group the silverside was 8% (P < 0.05) heavier in entires. In both castrates and entires, there appeared to be an increase in the percentage of the rump as the animals grew from 13 to 19 months of age. (C) 2001 Elsevier Science Ltd. All rights reserved.

Part 2. Carcass composition and fatty acid profiles of adipose tissue of male goats: effects of genotype and liveweight at slaughter

The dissected carcass composition and fatty acid profiles of intermuscular fat from 110 male goat kids from six genotypes i.e. Boer x Angora (BA), Boer x Feral (BF), Boer x Saanen (BS), Feral x Feral (1717), Saanen x Angora (SA) and Saanen x Feral (SF) and two slaughter weight groups i.e. Capretto and Chevon (liveweight at slaughter 14-22 and 30-35 kg, respectively) were compared. Carcass tissue distribution for various genotypes was: muscle (63-66%), fat (10-13%) and bone (21-24%). Genotype significantly (P < 0.05) influenced the carcass composition; BA and FF carcasses had significantly higher muscle to bone ratio, while carcasses from BS kids were leaner compared to other genotypes. However, the two slaughter weight groups did not differ significantly (P > 0.05) in terms of carcass composition, when compared at the same carcass weight. In the present study, significant (P < 0.01) correlations were observed between percentage of muscle, fat and bone in most of the primal cuts and that in the carcass side. The main saturated fatty acids (SFAs) identified were palmitic (16:0) and stearic acid (18:0), while oleic acid (18: 1, omega9) was the main unsaturated fatty acid (UFA) in the intermuscular fat from goat kids. There were significant (P < 0.05) differences between genotypes in the proportions of individual fatty acids. Adipose tissue from BS kids had significantly higher UFAs (mainly oleic acid) and thus had a significantly lower melting point compared to other genotypes. There were significantly higher proportions of palmitic acid (35%) in the adipose tissue from Capretto kids compared to that from Chevon kids (22%). The concentration of UFAs increased in the adipose tissue from Capretto to Chevon carcasses. (C) 2003 Elsevier Science B.V. All rights reserved.

The role of angiogenesis in prostate development and the pathogenesis of prostate cancer

New vessel formation, a highly-regulated, active process commencing in the embryo and evident notably during the pubertal growth spurt, is essential for normal prostate development. Reactivation of this process in response to physiological stimuli, particularly hypoxia in mature tissues, occurs with new vessels forming principally from stromal components. Although angiogenesis is complex, putatively involving a multitude of angiogenic factors and inhibitors, there is powerful evidence of the importance of the VEGF system in the development of both the normal prostate and prostate cancer. Recent advances include an understanding of how castration acts through the VEGF system to inhibit angiogenesis. Stromal-endothelial and epithelial-endothelial interactions are just beginning to be investigated. A better understanding of how physiological angiogenesis is controlled should help to provide further insights into the mechanism of disregulated angiogenesis in tumours. Ultimately, new antiangiogenic agents are likely to find a role in the management of patients with prostate cancer.

The fatty acid composition of muscle and adipose tissues from entire and castrated male Boer goats raised in Australia

The fatty acid composition of longissimus thoracis (LT) muscle and adipose tissues (subcutaneous and intermuscular fat) from castrated and entire male Boer goat bucks was investigated. Sixty Boer bucks in groups of between three and five animals were slaughtered at 5, 15, 30, 45, 60, 75, 90 and 105 kg live weight (5 and 15 kg animals were not castrated). The fatty acid composition of LT muscle from castrated and entire Boers was significantly affected by slaughter weight. The fatty acid content of LT muscle and subcutaneous and intermuscular fat from both castrated and entire Boer bucks was primarily composed of oleic acid followed by palmitic and stearic acid. Both oleic and palmitic acid increased with slaughter weight whereas stearic acid decreased. LT muscle from castrated Boer bucks contained higher amounts of desirable fatty acids. In contrast to slaughter weight, castration of Boer bucks resulted in only minor changes in fatty acid composition of adipose tissues. It can be concluded that slaughter weight plays a role in changing the fatty acid composition of LT muscle and adipose tissues from Boer bucks.

Testicular development of Zebu bulls after chronic treatment with a gonadotropin-releasing hormone agonist

The objective was to compare testis characteristics of Zebu bulls treated with the GnRH agonist, deslorelin, at different times and for different durations during their development. An additional objective was to determine the usefulness of a stain for the transcription factor GATA-binding protein 4 (GATA-4) as a specific marker for Sertoli cell nuclei in cattle. Bulls (54) were allocated to nine groups (n = 6) and received s.c. deslorelin implants as follows: G1 = from birth to 3 mo of age; G2 = from 3 to 6 mo; G3 = from 6 to 9 mo; G4 = from 9 to 12 mo; G5 = from birth to 15 mo; G6 = from 3 to 15 mo; G7 = from 6 to 15 mo; G8 = from 12 to 15 mo; and G9 (control) = no implant. Bulls were castrated at 19 mo of age. Paraffin sections (10 mu m) were subjected to quantitative morphometry and GATA-4 immunohistochemistry. At castration, all bulls in the control group (6/6) had attained puberty (scrotal circumference ! 28 cm), whereas a smaller proportion (P < 0.05) had reached puberty in G2 (2/5) and G6 (1/ 6). Bulls in G2 and G6 also had a lesser (P < 0.05) testis weight compared with the control group. Total volume of seminiferous epithelium and total daily sperm production in G2 and G6 were only half that observed in the control group. Spermatids were observed in less than 50% of seminiferous tubules in G2, G6, and G7 compared with 82% in the control group (P < 0.05). Staining for GATA-4 was specific for and abundant in the Sertoli cell nucleus in both pre- and postpubertal bulls, and no other cell nucleus inside the seminiferous tubule was positive for GATA-4. Total number of Sertoli cells was not affected by treatment (P = 0.45), but nuclear volume was smaller in G2 and G6 (P < 0.05) compared with the control group. In conclusion, treatment of Zebu bulls with deslorelin had no apparent beneficial effect on testis development and delayed puberty when treatment was initiated at 3 mo of age. Staining for GATA-4 was a useful method for identifying and quantifying Sertoli cell nuclei in both pre- and postpubertal bulls.

Total cholesterol concentrations of the muscles in castrated Boer goats

Goat meat is an important source of animal protein and Boer goats are the most widespread breed of meat goats. Cholesterol in meat is a potential cause of human disease and little is known about the cholesterol concentration in different goat muscles. As animals gain bodyweight the amount of cholesterol in their tissues generally increases and can vary for different tissues. Therefore, the aim of this experiment was to determine the effect of slaughter weight and muscle type on total cholesterol concentrations in three muscles (longissimus thoracic, infraspinatus and biceps femoris) taken from castrated male Boer goats in Australia. The goats were grazed on a mixture of native pasture and Rhodes grass (Chloris gayana) and had access to lucerne and commercial goat pellets (CP 18%; ME 12.3 MJ/kg DM). The muscles were dissected from 24 goats slaughtered in groups of 4 or 5 animals at 30, 45, 60, 75 and 90 kg liveweight. Total cholesterol concentrations were then determined using high performance liquid chromatography (HPLC). Total cholesterol concentrations decreased (P < 0.01) with an increase in slaughter weight for the longissimus thoracic, infraspinatus and biceps femoris muscles. Significant differences (P < 0.01) were recorded in the total cholesterol concentrations for the three muscles studied. The average total cholesterol concentrations ranged from 55 to 60 mg/100 g for the longissimus thoracic, 69 to 88 mg/100g for infraspinatus and 65 to 82 mg/100 g for the biceps femoris muscles. These results are important for consumers of goat meat as total cholesterol concentrations vary between different muscles taken from animals slaughtered at different weights and the concentrations are higher in muscles taken from lighter and younger animals. Therefore, health conscious consumers of meat, concerned about the cholesterol content of their diet, should consume meat from the longissimus thoracic muscles of heavier or older goats. (c) 2005 Elsevier B.V. All rights reserved.