Seasonal changes in RFamide-related peptide-3 neurons in the hypothalamus of a seasonally breeding marsupial species, the brushtail possum (Trichosurus vulpecula)

2013 ◽  
Vol 521 (13) ◽  
pp. 3030-3041 ◽  
Author(s):  
Anan A. Harbid ◽  
Bernie J. McLeod ◽  
Alain Caraty ◽  
Greg M. Anderson
Reproduction ◽  
2001 ◽  
pp. 373-388 ◽  
Author(s):  
M Ricci ◽  
WG Breed

The flagellum of a mammalian spermatozoon consists of a central axoneme surrounded by two cytoskeletal structures, the outer dense fibres and the fibrous sheath, which may aid in sperm motility or stability. In this study the outer dense fibres and fibrous sheath were isolated and partially characterized in a marsupial species, the brushtail possum (Trichosurus vulpecula). Spermatozoa from the cauda epididymidis were decapitated by sonication, and the head and tail fractions were separated by centrifugation over a 20, 40 and 60% (w/v) sucrose density gradient. After confirming sperm tail purity by Nomarski microscopy, the tails were incubated in either SDS-dithiothreitol to isolate the outer dense fibres or urea-dithiothreitol to isolate the fibrous sheaths. Purified outer dense fibres and fibrous sheaths were solubilized in SDS and beta-mercaptoethanol and proteins were separated by one-dimensional PAGE. Coomassie blue staining showed that the outer dense fibres were composed of seven major proteins (molecular masses: 73, 58, 55, 54, 52, 41 and 16 kDa), and the fibrous sheath was composed of 12 major proteins (molecular masses: 106, 76, 66, 62, 55, 53, 52, 46, 40, 30, 28 and 16 kDa). A polyclonal antibody to the fibrous sheath proteins showed strong crossreactivity with those of fibrous sheath from spermatozoa of several other marsupial species, as well as those from laboratory rats. Subsequent western blotting identified the immunoreactive 76 and 62 kDa proteins from all species, thus indicating their high conservation between species. No crossreactivity of the fibrous sheath antibody to any other cytoskeletal structures, including the outer dense fibres, mid-piece fibre network or connecting laminae, or to the acrosome or underlying subacrosomal material, was evident, indicating that the fibrous sheath proteins are localized to this structure alone. Further work is in progress to determine the extent of homology of these proteins to those in eutherian mammals.


2005 ◽  
Vol 72 (2) ◽  
pp. 470-478 ◽  
Author(s):  
Jo W. Fink ◽  
Bernie J. McLeod ◽  
Stephen J. Assinder ◽  
Laura J. Parry ◽  
Helen D. Nicholson

2005 ◽  
Vol 17 (6) ◽  
pp. 603 ◽  
Author(s):  
Jean D. Wilson ◽  
Geoffrey Shaw ◽  
Marilyn B. Renfree ◽  
Richard J. Auchus ◽  
Michael W. Leihy ◽  
...  

The testicular androgen 5α-androstane-3α,17β-diol (androstanediol) mediates virilisation in pouch young of a marsupial, the tammar wallaby, and is the principal androgen formed in immature rodent testes. To chart the pattern of androstanediol formation in another marsupial species, the testes or fragments of testes from brushtail possums (Trichosurus vulpecula) that spanned the age range from early pouch young to mature adults were incubated with 3H-progesterone and the products were identified by high-performance liquid chromatography. The only 19-carbon steroids identified in pouch young and adult testes were the Δ4-3-keto-steroids testosterone and androstenedione. However, androstanediol and another 5α-reduced androgen (androsterone) were synthesised by testes from Day 87–200 males and these appeared to be formed from the 5α-reduction and 3-keto reduction of testosterone and androstenedione. In the prostate and glans penis of the immature male, 3H-androstanediol was converted to dihydrotestosterone. We conclude that the timing of androstanediol formation in the possum testis resembles the process in rodents rather than in the tammar wallaby and that any androstanediol in the circulation probably acts in target tissues via conversion to dihydrotestosterone.


2008 ◽  
Vol 20 (9) ◽  
pp. 29
Author(s):  
H. Martyn ◽  
K. Pugazhenthi ◽  
B. McLeod ◽  
H. D. Nicholson

Benign Prostatic Hyperplasia is an enlargement of the prostate affecting the ageing male population. The common Brushtail possum (Trichosurus vulpecula) has been identified as a possible model to study factors regulating prostate growth because its prostate grows and regresses seasonally. Transforming growth factor Beta 2 (TGF-β2) is present in human prostatic tissue. In vitro, TGF-β inhibits epithelial cell, but stimulates stromal cell proliferation (Mori et al. 1990). TGF-β2 binds to TGF-β receptor II (TGF-βRII), which then recruits the type 1 receptor (TGF-βRI) (Saez et al. 1998) The aim of this study was to identify any seasonal changes in expression of TGF-β2 and its receptors in the possum prostate. Six wild-caught possums were sacrificed in each of the months of January, March, May, July, September and November. The prostates were divided into a cranial and caudal region and immunohistochemistry and Western Blot analysis performed. In each animal the glandular and periurethral areas of the caudal and cranial prostates were examined separately. Immunohistochemistry identified the presence of TGF-β2 in both the stromal and epithelial cells of the glandular and periurethral areas of the cranial and caudal regions. In the cranial tissue, more immuno-positive stromal cells than epithelial cells were present, whereas in the caudal tissue immuno-reactivity was predominantly localised to the epithelial cells. Analysis of the western blots suggested that TGF-β2 expression was lowest immediately before and during the breeding season (March, May). Both TGF-βRI and TGF-βRII were identified in all regions of the prostate. Furthermore, immunohistochemistry revealed that the receptors were co-localised in the epithelial and stromal cells in all areas. TGF-β2 and its receptors are present in the possum prostate. TGF-β2 localisation varies between the caudal and cranial regions and as predicted from in vitro experiments TGF-β2 expression decreases during prostate growth. (1) Mori H. et al. (1990). The Prostate, 16, 71 - 80. (2) Saez C. et al. (1998). The Prostate, 37, 84 - 90.


Reproduction ◽  
2000 ◽  
pp. 1-14 ◽  
Author(s):  
M Lin ◽  
X Zhang ◽  
R Murdoch ◽  
RJ Aitken

A medium modified from eutherian systems was used to culture epididymal epithelial cells of the brushtail possum (Trichosurus vulpecula) for more than 2 months. Epididymal tubule fragments from the caput, corpus and cauda epididymides were used to generate cell monolayers. All three epididymal cell culture systems supported maturational changes in marsupial spermatozoa and enabled immature possum spermatozoa to differentiate from a T-shape to a streamlined shape, accompanied by the development of progressive motility after co-culture with 7-day-old cultured epididymal cell monolayers. This epididymal cell and sperm co-culture system for marsupial species may facilitate the identification of specific epithelial factors that affect sperm maturation, particularly in a species in which morphological maturation is readily visible.


2004 ◽  
Vol 16 (3) ◽  
pp. 307 ◽  
Author(s):  
Minjie Lin ◽  
Amanda Harman ◽  
Terry P. Fletcher

We investigated the cycle of the seminiferous epithelium in a marsupial, namely the brushtail possum (Trichosurus vulpecula), using semithin sections of seminiferous tubules embedded in Spurr’s resin. Using 14 steps of spermatid development as markers, we were able to class tubular cross-sections into 10 well-defined stages of the seminiferous epithelial cycle. The duration of one cycle was 13.5 days, as determined by injections of [3H]-thymidine and autoradiographic examination of the most advanced sperm cells at 2 h and 17 days after injection. The durations of stages I–X were 21.4, 66.4, 54.1, 47.0, 29.8, 28.5, 25.3, 25.0, 12.0 and 15.9 h, respectively, estimated by the relative percentage of occurrence of each stage. It was estimated that the life spans of the main germ cells were as follows: type B spermatogonia, 5.4 days; primary spermatocytes, 16.7 days; secondary spermatocytes, 0.7 days; and spermatids, 21.4 days. The results suggest that the kinetics of spermatogenesis in marsupials show a similar pattern to that in eutherians.


Sign in / Sign up

Export Citation Format

Share Document