Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) act on gonadal cells to promote steroidogenesis and gametogenesis. Clarifying the in vivo roles of LH and FSH permits a feasible approach to contraception involving selective blockade of gonadotropin action. One way to address these physiologically important problems is to generate mice with an isolated LH deficiency and compare them with existing FSH loss-of-function mice. To model human reproductive disorders involving loss of LH function and to define LH-responsive genes, we produced knockout mice lacking the hormone-specific LH␤-subunit. LH␤-null mice are viable but demonstrate postnatal defects in gonadal growth and function resulting in infertility. Mutant males have decreased testes size, prominent Leydig cell hypoplasia, defects in expression of genes encoding steroid biosynthesis pathway enzymes, and reduced testosterone levels. Furthermore, spermatogenesis is blocked at the round spermatid stage, causing a total absence of the elongated spermatids. Mutant female mice are hypogonadal and demonstrate decreased levels of serum estradiol and progesterone. Ovarian histology demonstrates normal thecal layer, defects in folliculogenesis including many degenerating antral follicles, and absence of corpora lutea. The defects in both sexes are not secondary to aberrant FSH regulation, because FSH levels were unaffected in null mice. Finally, both male and female null mice can be pharmacologically rescued by exogenous human chorionic gonadotropin, indicating that LH-responsiveness of the target cells is not irreversibly lost. Thus, LH␤ null mice represent a model to study the consequences of an isolated deficiency of LH ligand in reproduction, while retaining normal LH-responsiveness in target cells.is a member of the glycoprotein hormone family that includes follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (1, 2). These hormones are heterodimers consisting of a common ␣-subunit noncovalently linked to a hormone-specific ␤-subunit. LH binds to G-protein coupled receptors on Leydig cells in the testis and granulosa and theca cells in the ovary (1, 2). During pubertal and postpubertal gonad development, LH promotes steroidogenesis required for normal reproductive function (1, 2). Less clear are its functions during embryonic gonad development, although evidence suggests that early gonad development is independent of gonadotropin stimulation (3, 4).Intercellular communication within the testis is essential for normal spermatogenesis (5, 6). In response to FSH, the Sertoli cells secrete various factors that affect Leydig cell function (7,8). Similarly, testosterone produced from Leydig cells is required for spermatogenesis (7,8). In females, ovarian folliculogenesis and ovulation are critically dependent on synchronized activities of both FSH and LH (9, 10). Previously, we and others have used genetic models, including FSH␤, FSH-receptor, and LHreceptor knockout mice, to study the physiological roles of gonadotropins in gonad developmen...

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BackgroundEnterocytozoon bieneusi, the most commonly identified microsporidian species in humans, is also identified in livestock, birds, rodents, reptiles, companion animals, even wastewater. However, there is no information available on occurrence of E. bieneusi in pet chipmunks. The aim of the present study was to determine the genotypes, molecular characterization of E. bieneusi in pet chipmunks, and assess the zoonotic potential.ResultsA total of 279 fecal specimens were collected from chipmunks from seven pet shops and one breeding facility in Sichuan province, China. The prevalence for E. bieneusi was 17.6% (49/279) based on nested PCR targeting the internal transcribed spacer (ITS) region. The prevalence of E. bieneusi in chipmunks < 90 days of age was significantly higher than that in older chipmunks; however, differences among different sources and between genders were not significant. Eight genotypes of E. bieneusi were identified, including four known genotypes (D, Nig7, CHG9, and CHY1) and four novel genotypes (SCC-1 to 4). Phylogenetic analysis classified these genotypes into four distinct groups as follows: genotypes D and CHG9 clustered into group 1 of zoonotic potential; genotypes Nig7 and CHY1 clustered into group 6 and a new group, respectively; the four novel genotypes (SCC-1 to 4) formed a separate group named group 10.ConclusionsTo the best of our knowledge, this is the first study reporting the prevalence and genotypes of E. bieneusi in pet chipmunks in China. Genotypes D and Nig7, found in chipmunks in this study, have also been previously identified in humans, which suggests that chipmunks might play a role in the transmission of this pathogen to humans.

ObjectiveObesity has been associated with impaired immunity and increased susceptibility to bacterial infection. It also exerts protective effects against mortality secondary to acute lung injury. The effects of obesity on immune responses to acute lung injury induced by Escherichia coli were investigated to determine if the above‐mentioned differences in its effects were related to infection severity.MethodsDiet‐induced obesity (DIO) and lean control mice received intranasal instillations of 109 or 1010 CFUs of E. coli. The immune responses were examined at 0 h (uninfected), 24 h, and 96 h postinfection.ResultsFollowing infection, the DIO mice exhibited higher leukocyte, interleukin (IL)−10, IL‐6, and tumor necrosis factor‐α levels and more severe lung injury than the lean mice. Following inoculation with 1010 CFUs of E. coli, the DIO mice exhibited higher mortality and more severe inflammation‐induced injury than the lean mice, but no differences in E. coli counts were noted between the two groups. However, inoculated with 109 CFUs of E. coli, the DIO mice exhibited smaller E. coli burdens at 24 h and 96 h after infection, as well as lower concentrations of IL‐10 and tumor necrosis factor‐α and less severe lung injury at 96 h after infection.ConclusionsThe results support the emerging view that obesity may be beneficial in the setting of milder infection but detrimental in the setting of more severe infection.

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A B S T R A C TPorcine deltacoronavirus (PDCoV), is an emerging enteropathogenic coronavirus in pigs, that poses a novel threat to swine husbandry worldwide. Crucial to halting PDCoV transmission and infection is the development of effective therapies and vaccines. The spike (S) protein of coronavirus is the major target of host neutralizing antibodies, however the immunodominant neutralizing region in the S protein of PDCoV has not been defined.Here, three truncations of the PDCoV S protein were generated, the N-terminal domain of the S1 subunit (NTD, amino acids (aa) 50-286), the C-terminal domain of the S1 subunit (CTD, aa 278-616), and S2 subunit (aa 601-1087). The proteins were expressed using an E. coli expression system. Polyclonal antisera against the three recombinant proteins were produced in rabbits and mice. All three antisera were able to inhibit PDCoV infection in vitro, as determined by virus neutralization assay, fluorescent focus neutralization assay, and plaque-reduction neutralization. The CTD-specific antisera had the most potent PDCoV-neutralizing effect, indicating that the CTD region may contain the major neutralizing epitope(s) in the PDCoV S protein. Based on these findings, CTD may be a promising target for development of an effective vaccine against PDCoV infection in pigs.

Haemophilus parasuis is an opportunistic pathogen that causes Glässer's disease in swine, with polyserositis, meningitis, and arthritis. The high-temperature requirement A (HtrA)-like protease, which is involved in protein quality control, has been reported to be a virulence factor in many pathogens. In this study, we showed that HtrA of H. parasuis (HpHtrA) exhibited both chaperone and protease activities. Finally, nickel import ATP-binding protein (NikE), periplasmic dipeptide transport protein (DppA), and outer membrane protein A (OmpA) were identified as proteolytic substrates for HpHtrA. The protease activity reached its maximum at 40°C in a time-dependent manner. Disruption of the htrA gene from strain SC1401 affected tolerance to temperature stress and resistance to complement-mediated killing. Furthermore, increased autoagglutination and biofilm formation were detected in the htrA mutant. In addition, the htrA mutant was significantly attenuated in virulence in the murine model of infection. Together, these data demonstrate that HpHtrA plays an important role in the virulence of H. parasuis.