The postnatal leptin surge in mice is variable in both time and intensity and reflects nutritional status

Background/objectives The murine postnatal leptin surge occurs within the first 4 weeks of life and is critical for neuronal projection development within hypothalamic feeding circuits. Here we describe the influence of nutritional status on the timing and magnitude of the postnatal leptin surge in mice. Methods Plasma leptin concentrations were measured 1–3 times per week for the first 4 weeks of life in C57BL/6J pups reared in litters adjusted to 3 (small), 7–8 (normal), or 11–12 (large) pups per dam fed breeder chow or raised in litters of 7–8 by dams fed high-fat diet (HFD) ad libitum starting either prior to conception or at parturition. Results Mice raised in small litters become fatter than pups raised in either normal or large litters. The leptin surge in small litter pups starts earlier, lasts longer, and is dramatically larger in magnitude compared to normal litter pups, even when leptin concentrations are normalized to fat mass. In mice reared in large litters, weight gain is diminished and the surge is both significantly delayed and lower in magnitude compared to control pups. Pups reared by HFD-fed dams (starting preconception or at parturition) are fatter and have augmented leptin surge magnitude compared to pups suckled by chow-fed dams. Surge timing varies depending upon nutritional status of the pup; the source of the surge is primarily subcutaneous adipose tissue. At peak leptin surge, within each group, fat mass and plasma leptin are uncorrelated; in comparison with adults, pups overproduce leptin relative to fat mass. Plasma leptin elevation persists longer than previously described; at postnatal day 27 mice continue overproducing leptin relative to fat mass. Conclusions In mice, small litter size and maternal HFD feeding during the perinatal period augment the plasma leptin surge whereas large litter size is associated with a delayed surge of reduced magnitude.

Differences in gene expression and variable splicing events of ovaries between large and small litter size in Chinese Xiang pigs

Background Although lots of quantitative trait loci (QTLs) and genes present roles in litter size of some breeds, the information might not make it clear for the huge diversity of reproductive capability in pig breeds. To elucidate the inherent mechanisms of heterogeneity of reproductive capability in litter size of Xiang pig, we performed transcriptome analysis for the expression profile in ovaries using RNA-seq method. Results We identified 1,419 up-regulated and 1,376 down-regulated genes in Xiang pigs with large litter size. Among them, 1,010 differentially expressed genes (DEGs) were differently spliced between two groups with large or small litter sizes. Based on GO and KEGG analysis, numerous members of genes were gathered in ovarian steroidogenesis, steroid biosynthesis, oocyte maturation and reproduction processes. Conclusions Combined with gene biological function, twelve genes were found out that might be related with the reproductive capability of Xiang pig, of which, eleven genes were recognized as hub genes. These genes may play a role in promoting litter size by elevating steroid and peptide hormones supply through the ovary and facilitating the processes of ovulation and in vivo fertilization.

Factors Contributing To The Swimmer Puppy Syndrome Found in Labrador Retrievers

Background Swimmer puppy syndrome is a disease found in neonatal puppies mainly characterized by the inability to stand, but its direct cause is unknown. Since swimmer puppies were observed infrequently but continuously among the Labrador retriever colony at the Hokkaido Guide Dogs for the Blind Association in Japan, based on their birth record and pedigree, factors related to the onset of swimmer puppy syndrome in Labrador retrievers were examined. Results The total number of offspring over seven years was 436, of which 16 were swimmer puppies. Most of the affected puppies except one recovered steadily. As for the swimmer puppies, the litter size was significantly lower, and the body weights on the 10th and 28th day after delivery were significantly higher than the non-symptomatic puppies. These results suggested that the onset may be related to weight gain in the neonatal stages due to a small litter size. According to the genetic analysis, 26 ancestors common to the affected individuals were confirmed, but the causative individual could not be identified with the inbreeding coefficient. The heritability of the swimmer-puppy onset trait was 0.80, and the heritability for the the 10th -day body-weight trait was equally high at 0.78, both of which strongly suggest genetic involvement. Conclusions In this study, the onset of swimmer puppy syndrome in the Labrador retrievers was associated with litter size and early weight gain, and result of study suggests that genetic influence might be involved.

New records and distribution map of Gold-striped Frog, Lithodytes lineatus (Schneider, 1799) (Anura, Leptodactylidae), in an ecotonal zone in Mato Grosso, Brazil

Lithodytes lineatus (Schneider, 1799) is a small, litter-dwelling frog widely distributed in the Amazon Ecoregion and some transitional areas between the Amazon and Cerrado. Here we report seven new records of this species in a transitional zone between Amazon, Chiquitano Dry Forest and Cerrado ecoregions in the state of Mato Grosso, Brazil. These are the southernmost records of the species, expanding its distribution in 320 km from the nearest record in Bolivia.

Performance characteristics of sows fed enriched diet from weaning to service in a commercial flock

Fielded data from 40 sows together with obtained data from 1999 to 2005 we analysed to determine the performance of sows fed enriched diet from weaning to a service in a commercialflock. The data were on litter size at birth (LTZVT), litter size at weaning (LTZWN), weaning age (WNAGE) forrowing interval (FRINT), purity (PRTY) and reproductive life (PRODLF). Mean value of 9.44(no), 6.04(no), 31.874, 453.58d and 3.65yrs were obtained for LTZBT, LTZWN, WNAGE, FRINT and PRODLF respectively. The influence of parity on sow's performance was analyzed while mortality and sows efficiency of production were determined. Anagonistic relationship existed between production and reproduction traite. Mortality amongst piglets increased with weaning age. Over 80% of sows hold PRINT of less than 157 days, farrowed litters greater than 7 and 55% weaned litter size of over 8. Parity had no influence on sow's performancw. Sow efficiency of production indices showed that sows had 2 farrowing/year, a farrowing rate of 84% and small litter index of less than 17%. The findings of this study have indicated that better performance of sows can be achieved by giving enriched diet (flushing) from weaning to a service rather than the practice of flushing only few days to service

Фактори, що впливають на мертвонародження поросят у свиноматок великої білої породи

This study considers signs of a sow that affect the stillborn piglets number in the nest and the likelihood of stillbirth. The animals that were used for this study were kept on the pig farm of «Tavriys’ki svyni» LLC, located in the Skadovsky district (Kherson region, Ukraine). The experimental materials used for this study consisted of 100 animals from productive parent sows of the Large White pig. The reproductive indicators of each animal included in this study were evaluated. The total number of piglets at birth (both live and dead), i.e. total litter size and and sow farrowing number were monitored for the first eight farrows during the period of eleven years (2007–2017). Stillborn piglets were observed in 63.3 ± 1.7% of litter, and their average proportion in the nest was 11.5 ± 0.4%. The proportion of piglets born dead of the total piglets at birth obtained in this study is within the range of 5 to 15%, which has been previously noted for commercial pig farms in other countries. With an increase in the age of the sow (the number of farrowing’s), there was a gradual decrease in the proportion of the litter in which no stillborn piglet was observed (χ2 = 51.35; P < 0.001), and, conversely, the proportion of nests in which 2–4 stillborn piglets were recorded gradually increased (χ2 = 46.32; P < 0.001). The number of stillborn piglets and the frequency of stillborn piglets in the litter tended to increase in sows that had a large litter size at birth (in both cases: P < 0.001).The binary logistic regression analyses indicated that the probability of a piglet being stillborn was significantly associated with the farrowing number of the sow and the total number of piglets in the litter (χ2 = 155.00; P < 0.001). This model predicted well the presence of at least one stillborn piglet per litter (in 86.6% of cases) and more or less adequately predicted its absence (in 42.9%). Our results indicate that there is a significant interaction between the number of farrowing and the total size of the litter when determining the estimate of the proportion of stillborn piglets in the litter. The same predicted estimates can be obtained for a small litter in an older sow, or, conversely, for a large litter in a first-farrowing sow.

High laboratory mouse pre-weaning mortality associated with litter overlap, advanced mother age, small and large litters

High and variable pre-weaning mortality is a persistent problem among the main mouse strains used in biomedical research. If a modest 15% mortality rate is assumed across all mouse strains used in the EU, approximately 1 million more pups must be produced yearly to compensate for those which die. A few environmental and social factors have been identified as affecting pup mortality, but optimizing these factors does not cease the problem. This study is the first large study to mine data records from 219,975 pups from two breeding facilities to determine the major risk factors associated with mouse pre-weaning mortality. It was hypothesized that litter overlap (i.e. the presence of older siblings in the cage when new pups are born), a recurrent social configuration in trio-housed mice, is associated with increased newborn mortality, along with high mother age, large litter size, as well as a high number and age of older siblings in the cage. The estimated probability of pup death was two to seven percentage points higher in cages with compared to those without litter overlap. Litter overlap was associated with an increase in percentage of litter losses of 19% and 103%, respectively, in the two breeding facilities. Increased number and age of older siblings, high mother age, small litter size (less than four pups born) and large litter size (over 11 pups born) were associated with increased probability of pup death. Results suggest that common social cage configurations at breeding facilities are dangerous for the survivability of young mouse pups. The underlying mechanisms and strategies to avoid these situations should be further investigated.

Early postnatal overnutrition accelerates aging-associated epigenetic drift in pancreatic islets

Pancreatic islets of type 2 diabetes patients have altered DNA methylation, contributing to islet dysfunction and the onset of type 2 diabetes. The cause of these epigenetic alterations is largely unknown. We set out to test whether (i) islet DNA methylation would change with aging and (ii) early postnatal overnutrition would persistently alter DNA methylation. We performed genome-scale DNA methylation profiling in islets from postnatally over-nourished (suckled in a small litter) and control male mice at both postnatal day 21 and postnatal day 180. DNA methylation differences were validated using quantitative bisulfite pyrosequencing, and associations with expression were assessed by RT-PCR. We discovered that genomic regions that are hypermethylated in exocrine relative to endocrine pancreas tend to gain methylation in islets during aging (R2 = 0.33, P < 0.0001). These methylation differences were inversely correlated with mRNA expression of genes relevant to β cell function [including Rab3b (Ras-related protein Rab-3B), Cacnb3 (voltage-dependent L-type calcium channel subunit 3), Atp2a3 (sarcoplasmic/endoplasmic reticulum calcium ATPase 3) and Ins2 (insulin 2)]. Relative to control, small litter islets showed DNA methylation differences directly after weaning and in adulthood, but few of these were present at both ages. Surprisingly, we found substantial overlap of methylated loci caused by aging and small litter feeding, suggesting that the age-associated gain of DNA methylation happened much earlier in small litter islets than control islets. Our results provide the novel insights that aging-associated DNA methylation increases reflect an epigenetic drift toward the exocrine pancreas epigenome, and that early postnatal overnutrition may accelerate this process.

Changes in Ovary Transcriptome and Alternative splicing at estrus from Xiang pigs with Large and Small Litter Size

Background/AimsLitter size is one of the most important reproductive traits in pig breeding, which is affected by multiple genes and the environment. Ovaries are the most important reproductive organs and have a profound impact on the reproduction efficiency. Therefore, genetic differences in the ovaries may contribute to the observed differences in litter size. Although QTLs and candidate genes have been reported to affect the litter size in many pig breeds, however, the findings cannot elucidate the marked differences of the reproductive traits between breeds. The aim of present work is to elucidate the mechanisms of the differences for the reproductive traits and identify candidate genes associated with litter size in Xiang pig breed.MethodsThe changes in ovary transcriptome and alternative splicing were investigated at estrus between Xiang pigs with large and small litter size by RNA-seq technology. The RNA-seq results were confirmed by RT-qPCR method.ResultsWe detected 16,219 - 16,285 expressed genes and 12 types of alternative splicing (AS) events in Xiang pig samples. A total of 762 differentially expressed genes were identified by XL (Xiang pig group with larger litter size) vs XS (Xiang pig group with small litter size) sample comparisons. A total of 34 genes were upregulated and 728 genes were downregulated in XL ovary samples compared with the XS samples. Alternative splicing (AS) rates in XL samples were slightly lower than that observed in XS samples. Most of differentially expressed genes were differentially regulated on AS level. Eleven candidate genes were potentially identified to be related to Xiang pig fecundity and litter size, which may be closely related to the gonad development, oocyte maturation or embryo quality.ConclusionThe significant changes in the expression of the protein-coding genes and the level of alternative splicing in estrus ovarian transcriptome between XL and XS groups probably are the molecular mechanisms of phenotypic variation in litter size.