scholarly journals The XO and OY chromosome constitutions in the mouse

1968 ◽  
Vol 12 (2) ◽  
pp. 125-137 ◽  
Author(s):  
T. Morris
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Early Stage ◽  
Blastocyst Stage ◽  
Embryonic Mortality ◽  
Cell Stage ◽  
Large Group ◽  
Pregnant Females ◽  
The Mean

A study was made of reproductive performance and embryonic mortality in XO and XX females. In the stock used, the mean litter size of XO females (4·46) was greatly below that of XX ones (8·17). One series of pregnant females of both karyotypes was dissected after 15 days' gestation, and another series after 3½days' gestation. In the former, there was a significantly greater amount of embryonic mortality in XO females both before implantation and at the small and large mole stages. By far the greater amount occurred before implantation. The data from dissections after 3½ days' gestation concerned pre-implantation embryos, since normal embryos at this point are at the late morula or early blastocyst stage. The embryos from XO females contained a large group of obviously and characteristically abnormal ones; they comprised 60/280 of the embryos from XO females, compared with 4/189 of the XX ones. They appeared to have developed abnormally from a very early stage, probably the two-cell stage, and were considered to represent the missing OY class of zygotes. In addition, it was concluded that there was probably an abnormally low segregation of nullo-X gametes from XO females.

The Small Mammals of Little Nourlangie Rock, NT. V. The Effects of Fire

1981 ◽  
Vol 8 (3) ◽  
pp. 515 ◽  
Author(s):  
RJ Begg ◽  
KC Martin ◽  
NF Price
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Small Mammals ◽  
Pregnant Females ◽  
Preferred Habitat ◽  
Closed Forest ◽  
The Mean ◽  
Fuel Characteristics ◽  
Release Program

Following a capture-mark-release program (February 1977-June 1979) on Dasyurus hallucatus, Antechinus bilarni, Zyzomys argurus and Zyzomys woodwardi, the study area was burnt to determine the effects of fire on these species. The area was described in terms of fuel characteristics and details of the fire were recorded. Post-fire trapping began July 1979 and continued until July 1980 (15,600 trap-nights). A. bilarni was the only species to suffer an increased mortality immediately after the fire, but the number of animals known to be alive declined over the year following the fire, for all species except D. hallucatus. The fire affected reproduction in all four species, but in different ways. Breeding in D. hallucatus was delayed by 1 month, and the mean number of young leaving the pouch per female was lower than before the fire. A higher number of resident females kept recruitment up. Litter size in A. bilarni was not affected, but a reduced number of resident females meant that recruitment was halved. Zyzomys argurus and Z. woodwardi showed few lactating and pregnant females in July-August following the fire, and the numbers of juveniles were lower than in the previous two years. Following the fire, no detectable differences in body weight were recorded, but all species except D. hallucatus changed their preferred habitat, moving to the Scree Slope. Z. woodwardi was most affected, and moved from the Closed Forest.

The effects of red clover (Trifolium pratense var. redhead), white clover (Trifolium repens var. S 100) or perennial ryegrass (Lolium perenne var. S 23) on the reproductive performance of sheep

1973 ◽  
Vol 80 (2) ◽  
pp. 323-327 ◽  
Author(s):  
J. E. Newton ◽  
J. E. Betts
Keyword(s):  
Litter Size ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Reproductive Performance ◽  
White Clover ◽  
Trifolium Pratense ◽  
Red Clover ◽  
The Third ◽  
S 100 ◽  
The Mean

SummaryDuring 3 years, three groups of 20 Scottish half-bred ewes were grazed on perennial ryegrass, white clover or red clover. During this period the two legumes were oestrogenic, in terms of teat-length extension of wethers, but the perennial ryegrass was not. The white clover was only markedly oestrogenic when there was a high proportion of diseased leaves. The mean litter size and lambing percentage of the ewes grazed on red clover was significantly reduced. White clover, although it was oestrogenic, had no effect on mean litter size or lambing percentage. The mean litter size of the ewes on the perennial ryegrass was 2·35, 2·30 and 2·24, on the white clover was 2·20, 2·33 and 2·23 and on the red clover was 1middot;60, 1·67 and 1·78 for the three lambings. Lambing percentage of the ewes on the perennial ryegrass was 175, 225 and 218, on the white clover was 210, 222 and 189, and on the red clover was 160, 128 and 118 for the three lambings. The lambing date of the ewes grazing on the red clover was significantly later at the third lambing.

scholarly journals 37DEVELOPMENTAL POTENTIAL OF CLONE CELLS IN MURINE CLONE-FERTILIZED AGGREGATION CHIMERAS

2004 ◽  
Vol 16 (2) ◽  
pp. 141
Author(s):  
S. Eckardt ◽  
N.A. Leu ◽  
K.J. McLaughlin
Keyword(s):  
Early Stage ◽  
Cumulus Cell ◽  
Blastocyst Stage ◽  
Wild Type ◽  
Cell Stage ◽  
Developmental Potential ◽  
Preimplantation Stage ◽  
Transgenic Embryos ◽  
Clone Cells

In both murine and porcine preimplantation stage clones, mosaicism in gene expression has been observed, indicating variation in transcription of some genes between cells of the individual clone (Boiani M et al., 2002 Genes Dev. 16, 1209–1219; Park KW et al., 2002 Biol. Reprod. 66, 1001–1005). This observation raises the question as to whether all blastomeres within one early-stage clone are equivalent, or whether there are differences in developmental potential. To address this, we aggregated preimplantation-stage clone embryos with fertilized embryos and assessed contribution of Oct4-GFP expressing cells of clone origin in blastocysts and in vitro outgrowths. In normal embryos, the Oct4-GFP transgene is expressed during preimplantation stages and reflects expression of Oct4 protein. Mouse cumulus cell clones were produced from cells transgenic for Oct4-GFP (Szabó PE et al., 2002 Mech. Dev. 115, 157–160) as described (Boiani M et al., 2002 Genes Dev. 16, 1209–1219). Four-cell-stage clones and synchronous fertilized non-transgenic embryos were aggregated in micro-wells after removal of the zona pellucida using acid Tyrode’s solution. Aggregates were cultured to the blastocyst stage in -MEM supplemented with bovine serum albumin (0.4% w/v). All control chimeras produced from four-cell-stage fertilized non-transgenic and Oct4-GFP transgenic embryos formed blastocysts, and 15 of 20 had GFP-expressing cells. The majority of clone-wild-type aggregates developed to the blastocyst stage (35/40); however, contribution of GFP-expressing cells was observed in fewer blastocysts compared to controls (12/35; P<0.05). Contribution of GFP expressing clone cells to the ICM varied between 30% and 100% of cells as determined by subjective evaluation of GFP fluorescence overlaying bright-field images. During in vitro outgrowth formation of synchronous aggregation chimeras of clone and wild-type embryos, maintenance of clone contribution to the ICM mound was observed, but at a lower frequency (12% v. 34% at the blastocyst stage). The results suggest that aggregation with fertilized cells does not provide benefit to clone blastomeres during preimplantation stages. Possibly, clone blastomeres may not be competitive with wild-type blastomeres, or are developmentally asynchronous, which will be tested using asynchronous chimeras.

A COMPARISON OF FRESH AND FROZEN SEMEN IN THE INSEMINATION OF CONFINED SHEEP

1979 ◽  
Vol 59 (4) ◽  
pp. 685-691 ◽  
Author(s):  
G. A. LANGFORD ◽  
G. J. MARCUS ◽  
A. J. HACKETT ◽  
L. AINSWORTH ◽  
H. F. PETERS ◽  
...  
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Embryonic Mortality ◽  
Frozen Semen ◽  
Serum Gonadotropin ◽  
Early Embryonic Mortality ◽  
The Difference ◽  
Natural Service ◽  
Fresh Semen

The reproductive performance of crossbred sheep maintained in total confinement was compared after artificial insemination with fresh or frozen semen. Estrus was synchronized with progestagen-impregnated vaginal sponges and pregnant mares’ serum gonadotropin. Inseminations were performed 54 and 60 h after sponge removal. The fertility of ewes inseminated with fresh semen was significantly higher than of ewes inseminated with frozen semen. Conception rates, lambing rates and litter size were 83%, 78% and 2.2 using fresh semen and 65%, 43% and 1.8 using frozen semen. In a group of similar ewes bred by natural service, the lambing performance was comparable to that obtained with fresh semen. The difference between conception and lambing rates suggests an increase in early embryonic mortality when breeding with frozen semen and confirms the need for improved frozen semen technology.

Studies in sow reproduction 1. The effect of nutrition between weaning and remating on the reproductive performance of primiparous sows

1972 ◽  
Vol 15 (3) ◽  
pp. 259-264 ◽  
Author(s):  
P. H. Brooks ◽  
D. J. A. Cole
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Post Partum ◽  
Large White ◽  
The Mean ◽  
Sow Reproduction

SUMMARYFollowing weaning of their first litter at 42 days post partum, 36 Landrace × (Landrace × Large White) sows were fasted for 24 hr then allocated to one of three feed levels, 1·8, 2·7 and 3·6 kg food/day, until the day after mating. During pregnancy all the sows received 1·8 kg food/day.The incidence of infertility and anoestrus was greatest for sows fed 1·8 kg/day and least for sows fed 3·6 kg·day. Sows fed 1·8 kg/day took significantly (P < 0·01) longer (21·6 + 3·0 days) to return to oestrus than sows fed 3·6 kg/day (9·2 ± 2·2 days). The mean litter size for sows fed 1·8, 2·7 and 3·6 kg food/day was 9·4 ± 0·9, 10·1 ± 0·8 and 11·5 ± 0·6 piglets respectively, but these differences were not significant.

The reproductive performance of Red Sokoto goats in Nigeria

1979 ◽  
Vol 93 (3) ◽  
pp. 563-566 ◽  
Author(s):  
I. F. Adu ◽  
V. Buvanendran ◽  
C. A. M. Lakpini
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Multiple Births ◽  
Litter Weight ◽  
The Mean ◽  
Red Sokoto Goat

SUMMARYAn analysis has been made of the reproductive performance of Red Sokoto goat of Nigeria. Data are based on records of 140 kiddings from 96 does. Age at first kidding was 435 ± 18·9 days. The mean litter size at first kidding was 1·45. Prolificacy increased with parity, the kidding percentages from first to third parities being 141, 186 and 200 respectively. Doe weight was significantly correlated with litter size (r = – 0·27). Repeatabilities of litter size per doe kidding and of litter weight were negative. Heritability of litter size was 0·08 ± 0·02. Birth weights were low, the mean weight of kids during the 3 years ranging from 1·48 to 1·64 kg. Doe weight was related to litter weight in a manner such that litter weight as a proportion of doe weight tended to decline as doe weight increased. The ratio of litter weights of singles to twins at any given weight of the doe was 100:180. Kid mortality by 3 months of age was 30·8 %. Mortality among twins was only slightly higher than singles. However, mortality in kids born in multiple births (triplets and quadruplets) was much higher. Birth weights of surviving kids were significantly higher than of those that died.

The effect of food intake in the rearing period on the reproductive performance of heavy and light gilts from large litters

1989 ◽  
Vol 49 (2) ◽  
pp. 305-310 ◽  
Author(s):  
R. B. Ogle ◽  
Anne-Marie Dalin
Keyword(s):  
Food Intake ◽  
Reproductive Performance ◽  
Embryonic Mortality ◽  
Effect Of Food ◽  
The Mean

ABSTRACTSixty crossbred gilts, comprising 15 groups of four littermates from large litters (> 12 pigs) were used. The experiment was designed as a 2 × 2 factorial, with two initial live weights (light (L) or heavy (H)) and either a low (lp) or high (hp) plane of feeding during the rearing period and post mating within each litter group. The hp gilts were significantly heavier (P < 0·001) and had thicker backfat (P < 0·001) than the lp gilts at first oestrus. The Hhp gilts reached puberty 26·4 days earlier than the Hip gilts (P < 0·05). Level of food intake significantly influenced ovulation rates and total embryo numbers, the hp gilts shedding on average 2·4 more ova and having 1·9 more embryos than the lp gilts 28 to 35 days post mating (P < 0·05). However, due to somewhat higher embryonic mortality in the hp gilts, the mean number of live embryos was not significantly higher than for the lp gilts (P < 0·05).

299. Sensitivity of embryos to an environmental stressor, ammonium, is dependent on stage of temporal exposure

2005 ◽  
Vol 17 (9) ◽  
pp. 127
Author(s):  
D. L. Zander ◽  
J. G. Thompson ◽  
M. Lane
Keyword(s):  
Gene Expression ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Early Stage ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Stages Of Development ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Stage Embryo

Extended embryo culture in vitro may cause increased cellular perturbations resulting in poorer developmental outcomes. Exposure of embryos to ammonium throughout the entire pre-implantation period decreased cell number and ICM development, increased apoptosis and perturbs glucose metabolism. The aim of this study was to examine the relative susceptibility of the pre- and post-compaction stage embryo to these perturbations resulting from temporal exposure to ammonium. Mouse embryos (n = 350 per treatment) were collected from F1 female mice. Embryos were exposed to either control medium or medium with 300 μM ammonium for the entire culture period. Temporal treatments involved culture with or without ammonium, from the zygote to 2-cell stage, 2-cell to 8-cell stage, or the 8-cell to the blastocyst stage. At the blastocyst stage, ICM development, apoptosis, gene expression and glucose metabolism were assessed. Differences between treatments were determined using generalised linear modelling and LSD post-hoc tests. Exposure to ammonium at any stage did not affect blastocyst development. Exposure to ammonium pre-compaction significantly decreased both blastocyst and ICM cell number while these were unaffected when exposure occurred post-compaction. Levels of apoptosis were significantly increased when exposure to ammonium was continual to the blastocyst stage (6.5% compared to control 2.4%, P < 0.05) or from the zygote to the 2-cell stage (5.8%, P < 0.05). However, apoptosis was not altered during post-compaction exposure (2.8%). Glucose uptake was decreased by culture with ammonium at all stages of development (P < 0.001). Gene expression of GLUT1 in the blastocyst was not altered by ammonium while GLUT3 expression was significantly reduced by exposure at all stages of development (P < 0.01). The data presented suggests that the pre-compaction stage embryo is most susceptible to ammonium stress and the effects of this early stage exposure appear irreversible. Intriguingly, glucose uptake and GLUT3 expression at the blastocyst stage appear to be markers of ammonium exposure.

scholarly journals Embryo manipulation via assisted reproductive technology and epigenetic asymmetry in mammalian early development

2013 ◽  
Vol 368 (1609) ◽  
pp. 20120353 ◽  
Author(s):  
Takashi Kohda ◽  
Fumitoshi Ishino
Keyword(s):  
Assisted Reproductive Technology ◽  
Early Stage ◽  
Gene Activation ◽  
Reproductive Technology ◽  
Blastocyst Stage ◽  
Mammalian Development ◽  
Cell Stage ◽  
Genome Wide ◽  
Zygotic Gene ◽  
Developmental Risks

The early stage of mammalian development from fertilization to implantation is a period when global and differential changes in the epigenetic landscape occur in paternally and maternally derived genomes, respectively. The sperm and egg DNA methylation profiles are very different from each other, and just after fertilization, only the paternally derived genome is subjected to genome-wide hydroxylation of 5-methylcytosine, resulting in an epigenetic asymmetry in parentally derived genomes. Although most of these differences are not present by the blastocyst stage, presumably due to passive demethylation, the maintenance of genomic imprinting memory and X chromosome inactivation in this stage are of critical importance for post-implantation development. Zygotic gene activation from paternally or maternally derived genomes also starts around the two-cell stage, presumably in a different manner in each of them. It is during this period that embryo manipulation, including assisted reproductive technology, is normally performed; so it is critically important to determine whether embryo manipulation procedures increase developmental risks by disturbing subsequent gene expression during the embryonic and/or neonatal development stages. In this review, we discuss the effects of various embryo manipulation procedures applied at the fertilization stage in relation to the epigenetic asymmetry in pre-implantation development. In particular, we focus on the effects of intracytoplasmic sperm injection that can result in long-lasting transcriptome disturbances, at least in mice.

scholarly journals Fertilization and development of bovine oocytes grown in female SCID mice

Zygote ◽  
2005 ◽  
Vol 13 (4) ◽  
pp. 309-315 ◽  
Author(s):  
Shoichiro Senbon ◽  
Kyosuke Ishii ◽  
Yoshiyuki Fukumi ◽  
Takashi Miyano
Keyword(s):  
Chorionic Gonadotropin ◽  
Blastocyst Stage ◽  
Scid Mice ◽  
The Other ◽  
Cell Stage ◽  
Mean Diameter ◽  
Bovine Spermatozoa ◽  
The Mean ◽  
Equine Chorionic Gonadotropin ◽  
Bovine Oocytes

We previously reported that xenografted bovine secondary follicles developed to the antral stage in severe combined immunodeficient (SCID) mice. In the present study, bovine secondary follicles 100–240 μm in diameter were xenografted under the kidney capsules of female SCID mice for 6 and 8 weeks, and we examined the oocytes' fertilization and developmental abilities. Bovine follicles developed with prolongation of grafting and became significantly larger than those before grafting. Injection of equine chorionic gonadotropin (eCG) into host mice made some surviving follicles develop larger than the other follicles. Furthermore, bovine oocytes grew in the follicles, and the mean diameter of the oocytes was 100 μm or more at 6 and 8 weeks of transplantation. Bovine oocytes that had grown in eCG-stimulated SCID mice 8 weeks after grafting were subjected to maturation culture. Some of the oocytes that had grown to 110 μm or more matured to the second metaphase (7% of oocytes 110–119 μm and 44% of those >120 μm). When the oocytes were inseminated with bovine spermatozoa, 15% (6/39) formed a female and a male pronucleus, and 2 days after insemination 24% (18/75) of oocytes cleaved and 2% (2/75) developed to the 5- to 8-cell stage. However, no embryo reached the blastocyst stage. These results indicate that bovine oocytes grown in SCID mice could be fertilized but acquired insufficient competence for embryonic development in the present conditions.

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