Pup Mortality Research Articles

Role of helminthes in canine pup mortality

Parasitism was the most encountered disease condition in all over the world. Out of 77 pup post-mortem examination, three (3.89 per cent) died due to helminthiasis (Two toxocarosis, one toxocarosis and ancylostomiosis). These were a 40 days old male non-descript and two 30 days old non-descript. Pale mucous membranes, anorexia, dullness and depression in all three pups, ascites in one pup and severe emaciation in another pup were observed. Severe anaemia, leucocytosis with neutrophilia, hypoproteinemia and hypoalbuminaemia were also recorded.

Effect of supplementation with organic acids on productive and reproductive parameters in guinea pigs

Guinea pig production systems demand organic alternatives to improve their productivity, due to the increased demands of this type of livestock operations. The present study aimed to evaluate the effect of organic acids on the productive and reproductive indices in reproductive Guinea pigs in an intensive breeding farm in Lima. 60 pools were used with 10 Guinea pigs in each one (9 females and one male). They were randomly divided into 4 treatment groups: T1: 1mL/L, T2: 2mL/L, T3: 4mL/L; all with 15 pools in total (5 pools each with dosage of 5, 10 and 15 days, respectively), and T4: Control (15 pools without dosage); the observation period was 3 months. No significant difference was found (p> 0.05) between treatments for weight gain, percentage of maternal mortality, percentage of abortions, percentage of pregnancy, number of offspring born and percentage of viability. For the percentage of mortality of pups and average weight of the offspring, a significant difference was found (p <0.05), demonstrating that T3 reached a higher weight index at birth of offspring (T3: 147.7 / 142.7 / 146.8g) and lower percentage of mortality in rabbits (T3: 0 / 1.8 / 3.0%). No significant difference was found in terms of dosing days. It is concluded that supplementation with organic acids with T3 (4mL/L) improved the weight at birth of the offspring and the mortality percentage in kits.

Causes of Mortality in a Harbor Seal (Phoca vitulina) Population at Equilibrium

The harbor seal (Phoca vitulina richardii) population in the Salish Sea has been at equilibrium since the mid-1990s. This stable population of marine mammals resides relatively close to shore near a large human population and offers a novel opportunity to evaluate whether disease acts in a density-dependent manner to limit population growth. We conducted a retrospective analysis of harbor seal stranding and necropsy findings in the San Juan Islands sub-population to assess age-related stranding trends and causes of mortality. Between January 1, 2002 and December 31, 2018, we detected 882 harbor seals that stranded and died in San Juan County and conducted necropsies on 244 of these animals to determine primary and contributing causes of death. Age-related seasonal patterns of stranded animals were evident, with pups found in the summer, weaned pups primarily recovered during fall, and adults and sub-adults recovered in summer and fall. Pups were the most vulnerable to mortality (64% of strandings). Pups predominantly died of nutritional causes (emaciation) (70%), whereas sub-adults and adults presented primarily with clinical signs and gross lesions of infectious disease (42%) and with non-anthropogenic trauma (27%). Primary causes of weaned pup mortality were distributed equally among nutritional, infectious, non-anthropogenic trauma, and anthropogenic trauma categories. Nutritional causes of mortality in pups were likely related to limitations in mid- and late-gestational maternal nutrition, post-partum mismothering, or maternal separation possibly related to human disturbance. Infectious causes were contributing factors in 33% of pups dying of nutritional causes (primarily emaciation–malnutrition syndrome), suggesting an interaction between poor nutritional condition and enhanced susceptibility to infectious diseases. Additional primary causes of harbor seal mortality were related to congenital disorders, predation, human interaction, and infections, including zoonotic and multidrug-resistant pathogens. Bottom-up nutritional limitations for pups, in part possibly related to human disturbance, as well as top-down predatory influences (likely under-represented through strandings) and infectious disease, are important regulators of population growth in this stable, recovered marine mammal population.

SAT-020 Fluoxetine Administration Influences Serotonin-Driven Bone Remodeling During Lactation and Pregnancy Outcome in Mice

Selective serotonin reuptake inhibitors (SSRI) are the most commonly prescribed class of antidepressants during pregnancy and lactation. SSRI decrease bone mineral density (BMD) across all ages and sexes. Lactation is also characterized by increased bone resorption to mobilize calcium due to the demands of lactation and achieves this via a serotonin-induced hormonal cascade. This serotonin-mediated bone loss is normally restored after weaning but is persistent when an SSRI is administered during the peripartum period. We hypothesize that the long-term BMD loss associated with fluoxetine administration during lactation will be seen in two sequential lactations and will have a more dramatic effect on maternal bone loss after the second lactation at both weaning and 3 months post-weaning. Female C57BL/6 mice were randomized to receive the SSRI fluoxetine hydrochloride (20 mg/kg) or saline daily from the beginning of pregnancy (E0), determined by the presence of a vaginal mucous plug, through the end of lactation (D21). They were then given a 3-week rest period before undergoing a second lactation with the same study design. Each group is paired to an age-matched virgin cohort to provide a non-lactating control. This created the following treatments: saline dam (S), fluoxetine dam (F), saline virgin pair (SV), and fluoxetine virgin pair (FV). Dual-energy X-ray absorptiometry (DEXA) was used to measure BMD of all groups throughout the peripartum period. At the end of gestation (E17.5), BMD was decreased in both the F and FV groups, and the BMD of the FV group remained persistently lower than the SV group across all timepoints. Both the F and S groups exhibited a dramatic decrease in BMD between E17.5 and the beginning of lactation (D2), then a slight increase between mid-lactation (D10) and at weaning (D21). There was an overall interaction between treatment and time for all groups across the peripartum period (p<0.0001). During the first peripartum period, the F dams that were mated had significantly increased pregnancy loss (p=0.0041) and pup mortality post-parturition compared to S mice. Of the dams that were inseminated, determined by the presence of a mucus plug, 63% of successfully mated S dams (n=19) resulted in a full-term pregnancy. Of those S dams (n=12), 25% lost their entire litter at the beginning of lactation, and 75% maintained their litter until weaning. In the F dams that were successfully mated (n=37), only 35% resulted in a full-term pregnancy. We conclude that fluoxetine administration during the peripartum period decreases long-term maternal BMD and that fluoxetine exhibits a drug-specific effect on the dam resulting in a notably decreased incidence of a successful pregnancy.

MON-001 Peripartum Sertraline (Zoloft®) Increases Pup Mortality Immediately Postpartum

Peripartum and postpartum depression can be detrimental to both the mother and the developing child. Use of antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), is common during the peripartal period and SSRIs have been the leading prescribed antidepressant to treat maternal depression. One of the most commonly prescribed SSRIs is sertraline (Zoloft®) because of the limited fetal teratogenic effects observed, unlike maternal paroxetine (Paxil®) usage which can manifest in fetal cardiovascular defects. Fluoxetine (Prozac®), like sertraline, has previously been shown to have limited teratogenic effects, however, we have shown treatment with fluoxetine for the entire period of pregnancy and lactation in mice compromises pup bones at weaning resulting in decreased long bone length and head circumference. Furthermore, maternal fluoxetine usage results in a sustained reduction in maternal bone mineral density post weaning, which may lead to long-term osteopenia, putting the mother at risk for bone-related disorders later in life. We hypothesized sertraline, like fluoxetine, will compromise maternal bone postpartum and fetal bone development at weaning. Treatment with sertraline in C57BL/6 dams throughout pregnancy and lactation reduced litter size (5.4 pups/dam) and increased pup mortality during the first 24 hours postpartum (20% dead pups/litter) compared to controls (6.8 pups/dam, 5% dead pups/litter, respectively; P < 0.018). Maternal calcium transporters (Orai1 and Serca2) were downregulated in the mammary gland in sertraline-treated dams on day 21 of lactation (P < 0.0032). Together, our data suggests in utero pharmacological exposure to sertraline may induce a failure to thrive in the pups and alters calcium metabolism in the dam. SSRI exposure during pregnancy and lactation may adversely affect the developing neonate(s) as well as have lasting impacts on the mother.

Insulin therapy for hyperglycemia in neonatal sepsis using a preterm mouse model.

Stress-induced hyperglycemia is a frequent complication of neonatal sepsis. Hyperglycemia induces oxidative stress and immunosuppression. We investigated the glucose kinetics and effect of insulin administration during stress-induced hyperglycemia in a neonatal sepsis mouse model. A stock cecal slurry (CS) solution was prepared from adult cecums and 3.0mg of CS/g (LD40 ) was administered intraperitoneally to 4-day-old FVB mouse pups. Blood glucose levels were measured at 1.5, 3, 6, and 9h post-sepsis induction and compared with basal levels. Two different doses of ultrafast-acting insulin were administered subcutaneously, and blood glucose levels and survival rates were monitored. Blood glucose levels were significantly higher than those of baseline levels with a peak at 3h, which progressively decreased from 6 to 9h post-sepsis induction. Insulin treatment reduced post-sepsis-induced hyperglycemia at 1.5 and 3h. The mortality rate of CS-only pups (39%) was similar to that of CS+1 U/kg insulin pups (60%). However, the mortality rate of CS+5 U/kg insulin pups (82%) was significantly higher than that of CS-only pups. Marked hyperglycemia was induced immediately after post-sepsis induction, and the high-dose insulin treatment increased mortality post-induction. Stress-induced hyperglycemia could therefore be a physiological and protective response for preterm sepsis, and aggressive treatment of this hyperglycemia might be contraindicated.

Double deletion of the active zone proteins CAST/ELKS in the mouse forebrain causes high mortality of newborn pups

Presynaptic active zone cytomatrix proteins are essential elements of neurotransmitter release machinery that govern neural transmission. Among active zone proteins, cytomatrix at the active zone-associated structural protein (CAST) is known to regulate active zone size in retinal photoreceptors and neurotransmitter release by recruiting Ca2+ channels at various synapses. However, the role of ELKS—a protein from the same family as CAST—and the synergistic roles of CAST/ELKS have not been thoroughly investigated, particularly with regard to mouse behavior. Here, we generated ELKS conditional KO in mouse forebrain synapses by crossing ELKS flox mice with a CaMKII promoter-induced Cre line. Results showed that CAST is dominant at these synapses and that ELKS can support CAST function, but is less effective in the ELKS single KO. Pups of CAST/ELKS double KO in the forebrain were born in Mendelian rations but resulted in eventual death right after the birth. Anatomically, the forebrain neuronal compositions of CAST KO and CAST/ELKS double KO mice were indistinguishable, and the sensory neural network from whiskers on the face was identified as barrelette-like patches in the spinal trigeminal nucleus. Therefore, depletion of CAST and ELKS disrupts neurotransmission from sensory to motor networks, which can lead to deficits in exploration and failure to suckle.

Transcriptomic analysis investigating the interaction between peripheral serotonin and high-fat diet feeding on mammary gene expression in midlactation mice.

To understand the role of peripheral serotonin and its interaction with diet in midlactation mammary gene expression, our study uses tryptophan hydroxylase 1 knockout (Tph1-KO) mice fed a high-fat diet (HFD). It has previously been demonstrated that HFD feeding increases inflammatory and immune pathways in peak lactation mammary glands of mice and increases pup mortality in wild-type (WT) mice compared with dams fed a low-fat diet (LFD). Peripheral serotonin inhibition has been associated with resistance to obesity in male mice fed an HFD. Little is known about the function of Tph1 and how peripheral serotonin affects mammary gland function during pregnancy and lactation. In this study, WT and Tph1-KO models were used to investigate global transcriptomic changes in peak lactation mammary glands when dams were fed either an HFD or LFD. WT and Tph1-KO female mice were assigned to either an LFD or HFD beginning at 3 wk of age (n = 4/group). Dams were euthanized on lactation day 11. Differentially expressed genes (DEGs) were first filtered by adjusted P value (cutoff ≤ 0.05) and fold-change (FC, cutoff ≥2). Genes were further filtered by mean normalized read count with a cutoff 310. We did not observe many differentially expressed genes in WT and Tph1-KO dams fed LFD. However, 3,529 DEGs were observed between WT-HFD and Tph1-KO-HFD mice, including cell cycle regulation and MAPK pathways being significantly enriched. Further research is required to completely understand the physiological significance of our results on peak lactation mammary physiology and the contribution of serotonin.

Pup mortality in New Zealand sea lions (Phocarctos hookeri) at Enderby Island, Auckland Islands, 2013-18.

New Zealand sea lions (Phocarctos hookeri) are an endemic and endangered species. Pup mortality at Enderby Island (50.5°S, 166.28°E) in the New Zealand sub-Antarctic has been well studied, with subsequent investigations yielding more intricate detail of the causes of mortality, as new diagnostic methods become available. Klebsiella pneumoniae was first reported in 2001–02 at this site, causing a pup mortality epizootic and is now known to be present at several colonies. This bacterium is a common mucosal commensal of humans and animals, however the agent found in pups at necropsy is a hypervirulent strain, readily recognised in microbial culture as being hypermucoviscous. Infection causes septicaemia with a common syndrome of subsequent meningitis and polyarthritis. This investigation uses histopathology and microbiology, with new modalities such as matrix assisted laser desorption/ionisation—time of flight mass spectrometry to show that Klebsiella septicaemia could have historically been, and continues to be, the most important cause of pup mortality, but has been previously underrepresented due to the often cryptic presentation and sometimes peracute course of disease. Hypermucoviscous K. pneumoniae should be considered a serious threat to pup survival in the species, causing on average 60.2% of pup deaths annually at Enderby Island between 2013 and 2018, with likely more continuing mortality following pup dispersal and the cessation of the summer monitoring season. Less common causes of death included starvation (14.8%), trauma/asphyxiation (9.9%) and other infections (7%). This study forms the basis for further evaluation of risk factors for pup mortality in the species, with a view to developing active mitigation.

MVA-Vectored Pentameric Complex (PC) and gB Vaccines Improve Pregnancy Outcome after Guinea Pig CMV Challenge, but Only gB Vaccine Reduces Vertical Transmission.

(1) Background: A congenital cytomegalovirus (cCMV) vaccine is a major research priority, but the essential glycoprotein target(s) remain unclear. We compared CMV gB (gpgB), gH/gL (gp75/gL), and pentameric complex (gpPC, composed of gH/gL/GP129/GP131/GP133) vaccines in a guinea pig CMV (GPCMV) congenital infection model. (2) Methods: Modified vaccinia virus Ankara (MVA) vaccines expressing GPCMV glycoproteins were used to immunize GPCMV-seronegative, female Hartley guinea pigs (three-dose series, 3 × 107 pfu/dose). After pregnancy was established, the dams underwent an early third-trimester challenge with salivary gland (SG)-adapted GPCMV. (3) Results: All vaccines elicited GPCMV-specific binding and neutralizing antibodies. Preconception immunization resulted in 19.5-, 4.9-, and 698-fold reductions in maternal DNAemia in MVA-gp75/gL, MVA-gpPC and MVA-gpgB groups, respectively, at day 14, post-SG challenge. Vaccination improved pups’ birth weight and reduced mortality and congenital CMV transmission. In controls, cCMV infection was observed in 100% of pups (mean viral load in all visceral organs, 2.4 × 104 genomes/mg), versus 50% in the gB group (visceral viral load, 9.4 × 102 genomes/mg; p < 0.05). No significant reductions in congenital transmission were noted in the MVA-gp75/gL and MVA-gpPC groups. (4) Conclusions: MVA-vectored gB, gH/gL, and PC vaccines were immunogenic, and protected against maternal DNAemia and pup mortality. These results support the inclusion of multiple glycoprotein complexes in a cCMV vaccine.

Effect of variously-processed rubber seed meals on reproductive performance: The use of Sprague-Dawley laboratory rats as model for pigs

The study aimed to determine the potential adverse effects of variously-processed rubber seed meals on the reproductive performance, postnatal growth and offspring survival rate using the Sprague-Dawley laboratory rat as model for pigs. Eighteen Sprague-Dawley female rats with an average initial body weight of 154.0 g were randomly allotted into 6 groups designated as T1 control (no rubber seed meal), T2 raw rubber seed meal, T3 soaked rubber seed meal, T4 sundried rubber seed meal, T5 boiled rubber seed meal and T6 roasted rubber seed meal. The diets were prepared with various types of rubber seed meals incorporated at the level of 0 g kg-1 (control diet, T!) and 100 g kg-1 of each of the five rubber seed meal-containing diets. The study was conducted for 70 days and parameters studied included: feed intake, number of fertile females, pregnancy index, gestation length (length of pregnancy), number of pups born, number of pups born alive, live birth index and number of still births. Upon parturition (day 1), pups were individually counted, weighed and examined for external malformations. Other parameters evaluated were number of pubs weaned and mortality of pups. The inclusion of various types of rubber seed meals in the diets did not alter the general health of all the experimental rats. With the exception of rats on the T6 diet, all other rats recorded successful mating and pregnancies. There were no significant (p&gt;0.05) difference in the gestation length (22 to 23 days) and all the pregnant rats delivered normally. No external malformations were observed in any of the pups delivered. No significant (p&gt;0.05) differences in the maternal body weight (199.8 g), litter size (4.0 to 10), pup birth weight (4.88 to 7.07 g) and number of pups weaned (3.33 to 9.67) were observed. However, dietary treatments significantly (p&lt;0.05) influenced weaning weight (29.60 to 48.25 g) and post-natal mortality of pups, with those on the T1 (control) and the T4 diets having the highest mortalities of 2.67 and 2.33, respectively. Based on the findings of the present study, up to 100 g of the raw and the variously-processed rubber seed meals could be included in 1 kg diets of laboratory rats without compromising on the health and reproductive performance in terms of reproductive toxicity or complications in pregnancy, delivery and other reproductive indices studied.

CCR2 mediates the adverse effects of LPS in the pregnant mouse.

In our earlier work, we found that intrauterine (i.u.) and intraperitoneal (i.p.) injection of LPS (10-μg serotype 0111:B4) induced preterm labor (PTL) with high pup mortality, marked systemic inflammatory response and hypotension. Here, we used both i.u. and i.p. LPS models in pregnant wild-type (wt) and CCR2 knockout (CCR2-/-) mice on E16 to investigate the role played by the CCL2/CCR2 system in the response to LPS. Basally, lower numbers of monocytes and macrophages and higher numbers of neutrophils were found in the myometrium, placenta, and blood of CCR2-/- vs. wt mice. After i.u. LPS, parturition occurred at 14h in both groups of mice. At 7h post-injection, 70% of wt pups were dead vs. 10% of CCR2-/- pups, but at delivery 100% of wt and 90% of CCR2-/- pups were dead. Myometrial and placental monocytes and macrophages were generally lower in CCR2-/- mice, but this was less consistent in the circulation, lung, and liver. At 7h post-LPS, myometrial ERK activation was greater and JNK and p65 lower and the mRNA levels of chemokines were higher and of inflammatory cytokines lower in CCR2-/- vs. wt mice. Pup brain and placental inflammation were similar. Using the IP LPS model, we found that all measures of arterial pressure increased in CCR2-/- but declined in wt mice. These data suggest that the CCL2/CCR2 system plays a critical role in the cardiovascular response to LPS and contributes to pup death but does not influence the onset of inflammation-induced PTL.

Social environment as a cause of litter loss in laboratory mouse: A behavioural study

Perinatal mortality is a widespread problem in laboratory mouse breeding and is often manifested by the loss of the entire litter within the first days of life. High mortality is an animal health and welfare concern that violates the 3R principles of reduction and refinement. High pup mortality is often considered “normal” in mouse breeding and the underlying causes are poorly understood. This study investigated the role of the social environment on pup survival and parental behaviour in C57BL/6 mice. Before parturition, multiparous females were allocated to three treatments: single-housing (SH, n = 54) or group-housing in trios of two females and a male, with group-housing further divided into trios with (GH1, n = 20) or without (GH0, n = 35) the presence of another litter. Mouse behaviour was recorded from 24 h before to 24 h after parturition. Mouse breeding performance (offspring survival and weight) was analysed using logistic and generalized linear models, and behaviours using logistic and multivariable linear models. We confirmed previous findings of high mortality rates for all treatments, but the highest rates were found in GH1 where half of the litters were lost entirely. Social environment had an impact on breeding performance. On the one hand, the presence of adult cagemates in GH0 did not affect litter survival nor pup body weight at 20 days. Adult cagemates shared the work of breeding by performing nest building before and after litter birth, and parental care after birth. GH0 and GH1 dams were less frequently seen performing nest building before and after parturition than SH dams. GH0 and GH1 dams were also less frequently seen inside the nest and performing parental behaviour after parturition than were SH dams. On the other hand, the risks for litter and pup loss were dramatically increased by 2.3 and 1.8 times, respectively, in GH1 compared to GH0. Parturition lasted longer in GH1 than in GH0 treatment. While dam behaviour did not differ between GH1 and GH0, GH1 adult cagemates spent less time performing parental care than did GH0 cagemates. Plausible reasons for the higher mortality in the presence of another litter are insufficient parental care, competition for milk access, poor nest quality, and crushing of newborns by older pups in the nest. This study indicates that being born in a cage where there is already an older litter, so-called reproductive asynchrony, is a major risk factor for litter loss.

Advancing metabolism research to overcome low litter survival in metabolically stressed mice

Elucidating the mechanism underlying the transmission of metabolic disease to subsequent generations requires robust preclinical mouse breeding strategies. Western diets rich in fat and carbohydrates are contributing factors in the rise of diabetes and obesity rates worldwide. Therefore, determining the impact of Western diets consumed by parents on offspring and future generations is critical for understanding the perpetuation of these diseases. Specifically, epigenetic regulation and transgenerational inheritance of metabolic disease is an emerging field of study requiring robust murine models. However, a major challenge to transgenerational studies is offspring mortality, exacerbated by maternal stress during pregnancy. Here, we describe a challenge experienced in our metabolic research in Western diet-fed female mice leading to the loss of litters via pup mortality and cannibalism by the mother. Furthermore, our study evaluates various breeding schemes with pregnancy efficiency and refined husbandry techniques to overcome pup mortality and infanticide, to characterize dams' and pups' metabolic characteristics, and to determine the impact on physiology of dams under detailed breeding schemes.

Population growth of an endangered pinniped—the New Zealand sea lion (Phocarctos hookeri)—is limited more by high pup mortality than fisheries bycatch

AbstractThe endangered New Zealand sea lion, Phocarctos hookeri is killed as incidental bycatch in a trawl fishery operating near their second largest population on Campbell Island in New Zealand’s sub-Antarctic. Using the Potential Biological Removal (PBR) procedure to assess the sustainability of this bycatch for the sea lion population on Campbell Island indicated that annual bycatch estimates, particularly following the implementation of bycatch mitigation measures, are below the PBR threshold of 25 (derived using a precautionary approach). Preliminary Population Viability Analysis (PVA) modelling supported the finding that current bycatch levels, especially given a strong male bias (98%) in bycatch, are sustainable for this population. Models showed that reducing pup mortality through management actions, such as installing ramps in wallows where large numbers of pups drown, would lead to increased population growth. While obtaining more accurate data on population status and demographic parameters for the Campbell Island population should be a priority, this will take many years of research. The PBR and PVA tools demonstrate that contemporary conservation management should continue to focus on increasing pup survival while maintaining mitigation approaches that have reduced bycatch to low levels, together with high observer coverage to sustain confidence in annual bycatch estimates.

Fitness Consequences of Female Alternative Reproductive Tactics in House Mice (Mus musculus domesticus).

Alternative reproductive tactics (ARTs) are defined as discrete differences in morphological, physiological, and/or behavioral traits associated with reproduction that occur within the same sex and population. House mice provide a rare example of ARTs in females, which can rear their young either solitarily or together with one or several other females in a communal nest. We assessed the fitness consequences of communal and solitary breeding in a wild population to understand how the two tactics can be evolutionarily stable. Females switched between the two tactics (with more than 50% of all females having two or more litters using both tactics), pointing toward communal and solitary breeding being two tactics within a single strategy and not two genetically determined strategies. Communal breeding resulted in reduced pup survival and negatively impacted female reproductive success. Older and likely heavier females more often reared their litters solitarily, indicating that females use a condition-dependent strategy. Solitary breeding seems the more successful tactic, and only younger and likely less competitive females might opt for communal nursing, even at the cost of increased pup mortality. This study emphasizes the importance of analyzing phenotypic plasticity and its role in cooperation in the context of female ARTs.

Immune-mediated hookworm clearance and survival of a marine mammal decrease with warmer ocean temperatures.

Increases in ocean temperature are associated with changes in the distribution of fish stocks, and the foraging regimes and maternal attendance patterns of marine mammals. However, it is not well understood how these changes affect offspring health and survival. The maternal attendance patterns and immunity of South American fur seals were assessed in a rookery where hookworm disease is the main cause of pup mortality. Pups receiving higher levels of maternal attendance had a positive energy balance and a more reactive immune system. These pups were able to expel hookworms through a specific immune mediated mechanism and survived the infection. Maternal attendance was higher in years with low sea surface temperature, therefore, the mean hookworm burden and mortality increased with sea surface temperature over a 10-year period. We provide a mechanistic explanation regarding how changes in ocean temperature and maternal care affect infectious diseases dynamics in a marine mammal.

Impact of rising sea levels on Australian fur seals.

Global warming is leading to many unprecedented changes in the ocean-climate system. Sea levels are rising at an increasing rate and are amplifying the impact of storm surges along coastlines. As variability in the timing and strength of storm surges has been shown to affect pup mortality in the Australian fur seal (Arctocephalus pusillus doriferus), there is a need to identify the potential impacts of increased sea level and storm surges on the breeding areas of this important marine predator in Bass Strait, south-eastern Australia. Using high-resolution aerial photography and topographic data, the present study assessed the impacts of future inundation levels on both current and potential breeding habitats at each colony. Inundation from storm surges, based on a predicted rise in sea level, was modeled at each colony from 2012 to 2100. As sea level increases, progressively less severe storm surge conditions will be required to exceed current inundation levels and, thus, have the potential for greater impacts on pup mortality at Australian fur seal colonies. The results of the present study indicate that by 2100, a 1-in-10 year storm will inundate more habitat on average than a present-day 1-in-100 year storm. The study highlights the site-specific nature of storm surge impacts, and in particular the importance of local colony topography and surrounding bathymetry with small, low-lying colonies impacted the most. An increased severity of storm surges will result in either an increase in pup mortality rates associated with storm surges, or the dispersal of individuals to higher ground and/or new colonies.

Reproductive and developmental F1 toxicity following exposure of pubescent F0 male mice to bisphenol A alone and in a combination with X-rays irradiation

Exposure to environmental toxicants may affect reproduction and development of subsequent generations. This study was aimed at determining the male-mediated F1 effects induced following 8-weeks of subchronic exposure of F0 male mice to bisphenol A (BPA) alone and in a combination with X-rays irradiation (IR) started during their puberty.4.5 weeks old F0 male mice were exposed to BPA dissolved in ethyl alcohol and diluted in drinking water at the following doses: 5 mg/kg bw, 10 mg/kg bw, 20 mg/kg bw or irradiated with X-rays (0.05 Gy) or exposed to a combination of low doses of both agents (0.05 Gy + 5 mg/kg bw BPA). Immediately after the end of the 8 weeks exposure F0 males were caged with two unexposed females each. Three quarters of the mated females from each group were sacrificed 1 day before expected parturition for examination of prenatal development of the offspring. The remainder of the females from each group were allowed to deliver and rear litters. Pups of exposed males were monitored for postnatal development for 8 weeks. At 8–9 weeks of age 6–8 males from each group of F1 generation were sacrificed to determine sperm count and quality.The current results, compared to the earlier results, showed that exposure of pubescent males to BPA alone or in combination with irradiation may be more damaging to their offspring than the exposure of adult males. The exposure of pubescent males to BPA alone and in combination with irradiation significantly increased the frequency of abnormal skeletons of surviving fetuses, increased the percent of mortality of pups in the F1 generation, reduced the sperm motility of F1 males and may induce obesity. Additionally, the combined BPA and irradiation exposure reduced the number of total and live implantations, whereas the exposure to BPA alone disturbed the male:female sex ratio. The above results may be caused by genetic or by epigenetic mechanisms. Limitation of use of products including BPA, especially by children and teenagers, is strongly recommended.

The effects of dietary levels of genistein on ovarian follicle number and gene expression

Genistein is a phytoestrogen found in soy. We previously found that adult exposure to dietary levels of genistein affected gestation time, parturition time, litter size, pup weight, and pup mortality in CD-1 mice. The present study investigated the effects of adult genistein exposure on follicle number and gene expression in the ovaries of CD-1 mice. We found that exposure to genistein had no effect on follicle number, but it did affect the expression of apoptotic regulatory genes (Bax, Bcl-2, Bid, and Dffa) in the ovary.