Lack of Effect of Metyrapone and Exogenous Cortisol on Early Porcine Conceptus Development

In many species, including swine, fetal plasma glucocorticoids such as cortisol increase as term approaches and are responsible for final maturational changes in numerous tissues (e.g. Silver, 1990; Sangild et al. 1993, 1994; Fowden et al. 1995). On the contrary, excessive exposure to glucocorticoids during gestationmay cause intra-uterine growth retardation, developmental abnormalities or death, or lead to increased incidence of certain diseases during adult life (Blackburn et al. 1965; Reinisch et al. 1978; Seckl et al. 2000). Hence, one might speculate that a closely regulated glucocorticoid exposure is necessary throughout gestation to ensure appropriate development and survival (Klemcke et al. 1999). We have previously demonstrated in pregnant and cyclic pigs that intra-uterine cortisol increases 4- to 6.7-fold between days 10 and 19 of pregnancy (Klemcke et al. 1998). At this time (days 10–19) in conceptus (embryo plus associated extra-embryonic membranes) development, the blastocyst is undergoing quite dramatic changes (Marrable, 1971; Anderson, 1978; Anderson et al. 1993). Part of this development involves the allantois, which rapidly expands between days 18 and 30 owing to water accumulation (Bazer et al. 1981) that might in part result from Na+,K+-ATPase-generated water movement (Macknight & Leaf, 1977). Corticosteroids are known to regulate Na+,K+-ATPase in various tissues (e.g. Verrey et al. 1996)

Lack of Effect of Metyrapone and Exogenous Cortisol on Early Porcine Conceptus Development

In many species, including swine, fetal plasma glucocorticoids such as cortisol increase as term approaches and are responsible for final maturational changes in numerous tissues (e.g. Silver, 1990; Sangild et al. 1993, 1994; Fowden et al. 1995). On the contrary, excessive exposure to glucocorticoids during gestationmay cause intra-uterine growth retardation, developmental abnormalities or death, or lead to increased incidence of certain diseases during adult life (Blackburn et al. 1965; Reinisch et al. 1978; Seckl et al. 2000). Hence, one might speculate that a closely regulated glucocorticoid exposure is necessary throughout gestation to ensure appropriate development and survival (Klemcke et al. 1999). We have previously demonstrated in pregnant and cyclic pigs that intra-uterine cortisol increases 4- to 6.7-fold between days 10 and 19 of pregnancy (Klemcke et al. 1998). At this time (days 10–19) in conceptus (embryo plus associated extra-embryonic membranes) development, the blastocyst is undergoing quite dramatic changes (Marrable, 1971; Anderson, 1978; Anderson et al. 1993). Part of this development involves the allantois, which rapidly expands between days 18 and 30 owing to water accumulation (Bazer et al. 1981) that might in part result from Na+,K+-ATPase-generated water movement (Macknight & Leaf, 1977). Corticosteroids are known to regulate Na+,K+-ATPase in various tissues (e.g. Verrey et al. 1996)

Identification of Quantitative Trait Loci Affecting Female Reproductive Traits in a Multigeneration Meishan-White Composite Swine Population

A multigeneration crossbred Meishan- White composite resource population was used to identify quantitative trait loci (QTL) for age at first estrus (AP) and the components of litter size: ovulation rate (OR; number of ova released in an estrous period) and uterine capacity (UC). The population was established by reciprocally mating Meishan (ME) and White composite (WC) pigs. Resultant F1 females were mated to either ME or WC boars to produce backcross progeny (BC) of either ¾ WC ¼ ME or ¼ WC ¾ ME. To produce the next generation (F3) , ¾ WC ¼ ME animals were mated to ¼ WC ¾ ME animals yielding half-blood (½ WC ½ ME) progeny. A final generation (F4) was produced by inter se mating F3 animals. Measurements for AP and OR were recorded on 101 BC, 389 F3, and 110 F4 gilts, and UC data were from 101 BC and 110 F4 first parity litters. A genomic scan was conducted with markers (n = 157) spaced &#;20 cM apart. All parental, F1, BC, and F4 animals but only 84 F3 animals were genotyped and included in this study. The QTL analysis fitted a QTL at 1-cM intervals throughout the genome, and QTL effects were tested using approximate genome-wide significance levels. For OR, a significant (E[false positive] \u3c .05) QTL was detected on chromosome 8, suggestive (E[false positive] \u3c 1.0) QTL were detected on chromosomes 3 and 10, and two additional regions were detected that may possess a QTL (E[false positive] \u3c 2.0) on chromosomes 9 and 15. Two regions possessed suggestive evidence for QTL affecting AP on chromosomes 1 and 10, and one suggestive region on chromosome 8 was identified for UC. Further analyses of other populations of swine are necessary to determine the extent of allelic variation at the identified QTL

CP violation in J/ψ→ΛΛˉJ/\psi \rightarrow \Lambda \bar \Lambda

We study CP violation in $J/\psi \rightarrow \Lambda \bar{\Lambda}$ decay. This decay provides a good place to look for CP violation. Some observables are very sensitive to the $\Lambda$ electric dipole moment $d_\Lambda$ and therefore can be used to improve the experimental upper bound on $d_\Lambda$. CP violations in the lepton pair decays of $J/\psi$ and $\Upsilon$ are also discussed.Comment: 8 pages, RevTex, UM-P-92/113, OZ-92/3

Genetic differences in the frequency of the hinge variants of porcine IgA is breed dependent

The distribution of the IgAa and IgAb alleles of porcine IgA in over 160 randomly-selected animals revealed an abundance of heterozygotes but only two b/b homozygotes. Since the IgAb allotype is a splice site mutant lacking two-thirds of the hinge, this study tests the hypothesis that pigs with this genotype may be at a selective disadvantage while heterozygous individuals may be at some advantage. This hypothesis was tested by collecting data on 374 animals of known breed and often parentage. We show here that when breed was not considered, young animals of known parentage had genotypic frequencies identical to that expected for Mendelian alleles but that a/b heterozygotes were overrepresented in adults. However, when analyzed with regard to breed, a very strong association between breed and the frequency of the IgAa and IgAb alleles was discovered. Meishan and NIH minipigs were homozygous for IgA while heterozygotes predominated in Berkshire, Chester White, Durocs, Hampshire and Landrace. Animals homozygous for IgAb were best represented in the White Cross line. We show here that this very strong breed dependency of IgA allotypy in swine can produce a sample bias that can explain why only two b/b homozygotes (1.3%) were found in the 160 randomly-selected samples since the original samples came from primarily Landrace and Yorkshire animals. The expected frequency of b/b homozygotes in these breeds would be \u3c3%. Thus, the data presented here reject the hypothesis that swine homozygous for a trait that results in loss of two-thirds of the IgA hinge, are selected against and that heterozygotes are positively selected. Rather, the study shows that IgAa and IgAb appear to be simple, breed-dependent allotypic markers

CP Violation in Fermion Pair Decays of Neutral Boson Particles

We study CP violation in fermion pair decays of neutral boson particles with spin 0 or 1. We study a new asymmetry to measure CP violation in $\eta, K_L \rightarrow \mu^+\mu^-$ decays and discuss the possibility of measuring it experimentally. For the spin-1 particles case, we study CP violation in the decays of $J/\psi$ to $SU(3)$ octet baryon pairs. We show that these decays can be used to put stringent constraints on the electric dipole moments of $\Lambda$, $\Sigma$ and $\Xi$.Comment: 14p, OZ-93/22, UM-93/89, OITS 51