From:
Sukie Crandall
Date: 2008-11-13 21:28:58 UTC
Subject: [ferrethealth] abstracts (probably none this time for most vet clinicians)
To: fhl <ferrethealth@yahoogroups.com>
I know this is dated Sept. but it seems to have just come out (ditto
one from October):
BEGIN QUOTE
Reprod Domest Anim. 2008 Sep 10. [Epub ahead of print]
Chromatin Configurations in the Ferret Germinal Vesicle that Reflect
Developmental Competence for In Vitro Maturation.
Sun X, Li Z, Yi Y, Ding W, Chen J, Engelhardt JF, Leno GH.
Department of Anatomy and Cell Biology, Carver College of Medicine,
University of Iowa, Iowa City, IA, USA.
Contents In several mammalian species, the configuration of germinal
vesicle (GV) chromatin correlates with the developmental competence of
oocytes. Yet, no study has been published on the configuration of GV
chromatin in ferret, nor is it known whether a specific configuration
predicts meiotic competence in this species, in spite of the potential
importance of ferret cloning to the study of human disease and to
species conservation efforts. Here, we report on an analysis of the
chromatin configuration in ferret GV oocytes and on how they correlate
with meiotic development. Three distinct configurations were
identified based on the degree of chromatin condensation: (1)
fibrillar chromatin (FC), featuring strands of intertwined chromatin
occupying most of the visible GV region; (2) intermediate condensed
chromatin (ICC), characterized by dense, irregular chromatin masses
throughout the GV; and (3) condensed chromatin (CC), which is highly
compact and centered around the nucleolus. We also found that
chromatin configuration was related to the extent of association with
cumulus cells in cumulus-oocyte complexes; CC-configured oocytes were
most often surrounded by a compact cumulus layer and also a compact
corona but FC-configured oocytes were associated with neither. In
addition, increasing chromatin condensation corresponded to an
increase in oocyte diameter. Finally, following in vitro culture,
significantly more CC-configured oocytes underwent maturation to
meiotic metaphase II than did FC- or ICC-configured oocytes. We
conclude that, in ferret, chromatin condensation is related to the
sequential achievement of meiotic competencies during oocyte growth
and differentiation, and thus can be used as a predictor of competence.
PMID: 18992097
END QUOTE
http://www3.interscience.wiley.com/journal/121430821/abstract?CRETRY=1&SRETRY=0
---
BEGIN QUOTE
J Neurosci. 2008 Nov 5;28(45):11557-70.
Virtual adult ears reveal the roles of acoustical factors and
experience in auditory space map development.
Campbell RA, King AJ, Nodal FR, Schnupp JW, Carlile S, Doubell TP.
Department of Physiology, Anatomy and Genetics, Sherrington Building,
University of Oxford, Oxford, United Kingdom.
Auditory neurons in the superior colliculus (SC) respond
preferentially to sounds from restricted directions to form a map of
auditory space. The development of this representation is shaped by
sensory experience, but little is known about the relative
contribution of peripheral and central factors to the emergence of
adult responses. By recording from the SC of anesthetized ferrets at
different age points, we show that the map matures gradually after
birth; the spatial receptive fields (SRFs) become more sharply tuned
and topographic order emerges by the end of the second postnatal
month. Principal components analysis of the head-related transfer
function revealed that the time course of map development is mirrored
by the maturation of the spatial cues generated by the growing head
and external ears. However, using virtual acoustic space stimuli, we
show that these acoustical changes are not by themselves responsible
for the emergence of SC map topography. Presenting stimuli to infant
ferrets through virtual adult ears did not improve the order in the
representation of sound azimuth in the SC. But by using linear
discriminant analysis to compare different response properties across
age, we found that the SRFs of infant neurons nevertheless became more
adult-like when stimuli were delivered through virtual adult ears.
Hence, although the emergence of auditory topography is likely to
depend on refinements in neural circuitry, maturation of the structure
of the SRFs (particularly their spatial extent) can be largely
accounted for by changes in the acoustics associated with growth of
the head and ears.
PMID: 18987192
END QUOTE
http://www.jneurosci.org/cgi/content/full/28/45/11557
---
POLECAT COMPARISON:
BEGIN QUOTE:
Reprod Domest Anim. 2008 Oct 13. [Epub ahead of print]
Reproduction in the European Mink, Mustela lutreola: Oestrous
Cyclicity and Early Pregnancy.
Amstislavsky S, Lindeberg H, Ternovskaya Y, Zavjalov E, Zudova
G,Klochkov D, Gerlinskaya L.
Institute of Cytology and Genetics, Novosibirsk State University,
Novosibirsk, Russia.
Contents Despite efforts undertaken to conserve the endangered
European mink, its reproduction is still poorly studied. The aim was
to study its reproductive cyclicity, faecal progesterone concentration
and ovarian changes during early pregnancy, with the emphasis on the
pre-implantation period and implantation. During the 2004 breeding
season, oestrous cycle was monitored in 39 females as well as ovarian
changes during early pregnancy in 22 females. During the 2007 breeding
season, faecal progesterone concentration measured by radioimmunoassay
was monitored during pregnancy in 10 females throughout their
pregnancy. The breeding season 2004 started on March 18 and ended on
May 10, with the peak recorded in April. The duration of first oestrus
was 1-12 days. If not mated, the vast majority of females entered
second oestrus after 12-55 days. In general, relatively low faecal
progesterone values were detected in European mink; an average of
42.69 +/- 4.70 ng/g faeces in oestrous females with a maximum of
176.44 +/- 23.01 ng/g faeces on pregnancy day 12. anova indicated a
significant effect of the pregnancy stage. Post hoc comparisons with
Fisher least significant difference (LSD) test revealed that faecal
progesterone concentrations on days 8 and 12 post coitum (p.c.), but
not at the end of pregnancy (day 40), were higher when compared with
the initial oestrous level. Implantation in this species occurs on day
12 p.c. and was indicated by prominent uterine swellings and failure
to flush the uterine horns beyond this day. Advanced luteogenesis was
observed with prominent corpora lutea found in ovaries around the time
of implantation. To conclude, European mink is a seasonally
polyoestrous species; the early pregnancy of European mink resembles
that of European polecat, i.e. in both species, implantation occurs on
day 12 p.c. without any implantation delay.
PMID: 18992118
END QUOTE
http://www3.interscience.wiley.com/journal/121459351/abstract
Sukie (not a vet)
Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/fhc/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
[Non-text portions of this message have been removed]
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