Mental health of animal hoarders: a study of consecutive cases in New South Wales.

Objective The aim of this study was to review animal hoarding cases referred to the Royal Society for the Prevention of Cruelty to Animals (RSPCA) in New South Wales (NSW) to examine mental health factors that influence the development of animal hoarding and to consider strategies for dealing with such cases. Methods Data were gathered by RSPCA inspectors regarding consecutive cases referred to the agency over 2 years. Result Details were provided about animals and 50 identified hoarders (11 male, 39 female; mean age 57 years) on 48 properties. The mean number of animals per case was 53 (range 6-300). Fifteen participants (30%) were known to have had involvement with mental health or social services. Mental health factors appeared to contribute to animal hoarding in well over 50% of cases. Severe and moderate squalor were observed in 52% and 21% of dwellings assessed respectively, many with accumulated rubbish. Conclusions Animal hoarding is largely attributable to psychological and psychiatric problems. It is recommended that clinical services work alongside animal welfare inspectorates, assessing (and, where appropriate, treating) such problems. What is known about the topic? Animal hoarding is believed to be partly attributable to the hoarders having psychiatric or psychological problems, but relevant mental health assessment of hoarders is not usually arranged. Recidivism after removal of animals is nearly 100%. What does this paper add? The study confirms that animal hoarders commonly have mental health issues. However, RSPCA inspectors are not expected to screen for such issues or refer cases to mental health clinicians. What are the implications for practitioners? There is good reason to develop clinical services to help animal hoarders deal with their psychological or psychiatric problems.

A New Polygenic Model for Nonfamilial Colorectal Cancer Inheritance Based on the Genetic Architecture of the Azoxymethane-Induced Mouse Model.

The azoxymethane model of colorectal cancer (CRC) was used to gain insights into the genetic heterogeneity of nonfamilial CRC. We observed significant differences in susceptibility parameters across 40 mouse inbred strains, with 6 new and 18 of 24 previously identified mouse CRC modifier alleles detected using genome-wide association analysis. Tumor incidence varied in F1 as well as intercrosses and backcrosses between resistant and susceptible strains. Analysis of inheritance patterns indicates that resistance to CRC development is inherited as a dominant characteristic genome-wide, and that susceptibility appears to occur in individuals lacking a large-effect, or sufficient numbers of small-effect, polygenic resistance alleles. Our results suggest a new polygenic model for inheritance of nonfamilial CRC, and that genetic studies in humans aimed at identifying individuals with elevated susceptibility should be pursued through the lens of absence of dominant resistance alleles rather than for the presence of susceptibility alleles.

Is it time to think about the sodium glucose co-transporter 2 sympathetically?

Disturbances in glucose homeostasis are a key feature of the metabolic syndrome and type 2 diabetes. Renal glucose reabsorption is an important factor in glycaemic control. Glucose reabsorption in the proximal tubules is mediated by the sodium glucose co-transporter 2. The capacity for glucose reabsorption is increased in type 2 diabetes and contributes significantly to hyperglycaemia and impaired glucose control. Understanding the mechanisms underpinning the regulation of the sodium glucose co-transporter 2 is therefore of high clinical relevance. However, despite recent advances in the field and the availability of pharmacological inhibitors of this glucose transporter for the treatment of type 2 diabetes, the mechanisms that regulate sodium glucose co-transporter 2 expression are not fully understood. The sympathetic nervous system is an important modulator of glucose homeostasis, and sympathetic hyperactivity is a characteristic feature of obesity, the metabolic syndrome and type 2 diabetes. Sympathetic inhibition either achieved pharmacologically or by renal sympathetic denervation has been associated with improved glucose control. Importantly, sympathetic nerves innervate the proximal tubules of the kidney where they have been shown to regulate the expression of other transporters such as the sodium hydrogen exchanger 3. This review aims to explore the evidence for the regulation of sodium glucose co-transporter 2-mediated glucose reabsorption by the sympathetic nervous system.

The sld genetic defect: two intronic CA repeats promote insertion of the subsequent intron and mRNA decay.

The autosomal recessive mutation, sld, attenuates mucous cell expression in murine sublingual glands with corresponding effects on mucin 19 (Muc19). We conducted a systematic study including genetic mapping, sequencing, and functional analyses to elucidate a mutation to explain the sld phenotype in neonatal mice. Genetic mapping and gene expression analyses localized the sld mutation within the gene Muc19/Smgc, specifically attenuating Muc19 transcripts, and Muc19 knock-out mice mimic the sld phenotype in neonates. Muc19 transcription is unaffected in sld mice, whereas mRNA stability is markedly decreased. Decreased mRNA stability is not due to a defect in 3'-end processing nor to sequence differences in Muc19 transcripts. Comparative sequencing of the Muc19/Smgc gene identified four candidate intronic mutations within the Muc19 coding region. Minigene splicing assays revealed a novel splicing event in which insertion of two additional repeats within a CA repeat region of intron 53 of the sld genome enhances retention of intron 54, decreasing the levels of correctly spliced transcripts. Moreover, pateamine A, an inhibitor of nonsense-mediated mRNA decay, inhibits degradation of aberrant Muc19 transcripts. The mutation in intron 53 thus enhances aberrant splicing leading to degradation of aberrant transcripts and decreased Muc19 message stability, consistent with the sld phenotype. We propose a working model of the unique splicing event enhanced by the mutation, as well as putative explanations for the gradual but limited increase in Muc19 glycoprotein expression and its restricted localization to subpopulations of mucous cells in sld mice during postnatal gland development.

New outbred colony derived from Mus musculus castaneus to identify skin tumor susceptibility loci.

Susceptibility to tumor development varies among mice strains. Using inbred NIH and wild-derived outbred Mus spretus backcrosses, skin cancer-susceptibility loci were mapped [Nagase et al. 1995. Nat Genet 10: 424-429; Nagase et al. 1999. Proc Natl Acad Sci USA 96: 15032-15037], and Skts13 was identified as the Aurka gene using a conventional linkage in conjunction with haplotype analysis [Ewart-Toland et al. 2003. Nat Genet 34: 403-412]. In the present study, we examined another wild-derived outbred Mus musculus castaneus in which 10.3% of the analyzed SNPs showed heterogeneity among the colony. All mice examined were completely resistant to the two-stage skin carcinogenesis protocol using 7.12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA), and this resistant phenotype was dominant when we crossed them with the highly susceptible strain FVB. By scanning F1 backcross progeny between M. m. castaneus and FVB, we found a highly significant linkage for tumor multiplicity on Chromosome 4, which was overlapped with the Skts-fp1 locus, found in the previous study using FVB and PWK cross [Fujiwara et al. 2007. BMC Genet 8: 39]. The linkage was observed in all pedigrees from the five F1 founders, while the linkage for papilloma size on Chromosome 4 was mapped only in pedigrees from founders 1 and 2. By scanning the whole Chromosome 4 of the five F1 founders, founders 1- and 2-specific haplotype block was found between D4Mit293 (20.6 Mbp) and D4Mit171 (22.4 Mbp). In this study we exploited the outbred nature of M. m. castaneus stock to identify a haplotype contributing to papilloma size on mouse Chromosome 4. These data illustrate the strength of using outbred mice in identification of the genetic component of a mouse complex trait such as the skin cancer-susceptibility phenotype.

Restriction landmark genomic scanning (RLGS) spot identification by second generation virtual RLGS in multiple genomes with multiple enzyme combinations.

BACKGROUND: Restriction landmark genomic scanning (RLGS) is one of the most successfully applied methods for the identification of aberrant CpG island hypermethylation in cancer, as well as the identification of tissue specific methylation of CpG islands. However, a limitation to the utility of this method has been the ability to assign specific genomic sequences to RLGS spots, a process commonly referred to as "RLGS spot cloning." RESULTS: We report the development of a virtual RLGS method (vRLGS) that allows for RLGS spot identification in any sequenced genome and with any enzyme combination. We report significant improvements in predicting DNA fragment migration patterns by incorporating sequence information into the migration models, and demonstrate a median Euclidian distance between actual and predicted spot migration of 0.18 centimeters for the most complex human RLGS pattern. We report the confirmed identification of 795 human and 530 mouse RLGS spots for the most commonly used enzyme combinations. We also developed a method to filter the virtual spots to reduce the number of extra spots seen on a virtual profile for both the mouse and human genomes. We demonstrate use of this filter to simplify spot cloning and to assist in the identification of spots exhibiting tissue-specific methylation. CONCLUSION: The new vRLGS system reported here is highly robust for the identification of novel RLGS spots. The migration models developed are not specific to the genome being studied or the enzyme combination being used, making this tool broadly applicable. The identification of hundreds of mouse and human RLGS spot loci confirms the strong bias of RLGS studies to focus on CpG islands and provides a valuable resource to rapidly study their methylation.

Proteasomes and proteasome activator 200 kDa (PA200) accumulate on chromatin in response to ionizing radiation.

Proteasome activator 200 kDa (PA200) forms nuclear foci after exposure of cells to ionizing radiation and enhances proteasome activity in vitro. Within cells, it is unclear whether PA200 responds to radiation alone or in association with proteasomes. In the present study, we identified three forms of cellular PA200 (termed PA200i, ii and iii) at the mRNA and protein levels. Neither PA200ii nor PA200iii appears to associate with proteasomes. All detectable PA200i is associated with proteasomes, which indicates that PA200i and proteasomes function together within the cell. Consistent with this idea, we find that exposure of cells to radiation leads to an equivalent accumulation of both PA200i and core proteasomes on chromatin. This increase in PA200 and proteasomes on chromatin is not specific to the stage of cell cycle arrest since it occurs in cells that arrest in G(2)/M and cells that arrest in G(1)/S after exposure to radiation. These data provide evidence that PA200 and proteasomes function together within cells and respond to a specific radiation-induced damage independent of the stage of cell cycle arrest.

Expression and functional analysis of genes deregulated in mouse placental overgrowth models: Car2 and Ncam1.

Different causes, such as maternal diabetes, cloning by nuclear transfer, interspecific hybridization, and deletion of some genes such as Esx1, Ipl, or Cdkn1c, may underlie placental overgrowth. In a previous study, we carried out comparative gene expression analysis in three models of placental hyperplasias, cloning, interspecies hybridization (IHPD), and Esx1 deletion. This study identified a large number of genes that exhibited differential expression between normal and enlarged placentas; however, it remained unclear how altered expression of any specific gene was related to any specific placental phenotype. In the present study, we focused on two genes, Car2 and Ncam1, which both exhibited increased expression in interspecies and cloned hyperplastic placentas. Apart from a detailed expression analysis of both genes during normal murine placentation, we also assessed morphology of placentas that were null for Car2 or Ncam1. Finally, we attempted to rescue placental hyperplasia in a congenic model of IHPD by decreasing transcript levels of Car2 or Ncam1. In situ analysis showed that both genes are expressed mainly in the spongiotrophoblast, however, expression patterns exhibited significant variability during development. Contrary to expectations, homozygous deletion of either Car2 or Ncam1 did not result in placental phenotypes. However, expression analysis of Car3 and Ncam2, which can take over the function of Car2 and Ncam1, respectively, indicated a possible rescue mechanism, as Car3 and Ncam2 were expressed in spongiotrophoblast of Car2 and Ncam1 mutant placentas. On the other hand, downregulation of either Car2 or Ncam1 did not rescue any of the placental phenotypes of AT24 placentas, a congenic model for interspecies hybrid placentas. This strongly suggested that altered expression of Car2 and Ncam1 is a downstream event in placental hyperplasia.

Loci affecting male fertility in hybrids between Mus macedonicus and C57BL/6.

Male F1 hybrids between inbred strains and Mus macedonicus have very small testes and are sterile. Cytological analysis of testes shows very few meioses. To determine the genetic basis for this sterility, (C57BL/6J x Mus macedonics) F1 females were mated to males from C57BL/10J. In about half the male progeny no meiosis I was observed. About half of the animals that progressed through meiosis I showed other indications of low fertility and the balance appeared fertile. QTL analysis of the progeny suggested that loci on proximal Chrs 17 and X were involved in the sterility and a locus on Chr X in variation of body weight. There is also evidence that X//Y dissociation of the pseudo-autosomal region occurs. The QTLs on Chrs X and 17 together account for about 37% of the variance for testis weight. Congenic lines B.MAC-X(1-38), and B.MAC-17(1-23) have been constructed using a modified speed congenic approach. Testis tubules from B.MAC-X(1-38) are narrow and vacuolated. They contain only Sertoli cells and mitotically dividing spermatogonia. Very occasionally a meiotic metaphase can be observed, but no sperm are produced. Homozygous males from B.MAC-17(1-23) are sterile, producing sperm heads but no complete sperm.

Hermansky-Pudlak syndrome type 7 (HPS-7) results from mutant dysbindin, a member of the biogenesis of lysosome-related organelles complex 1 (BLOC-1).

Hermansky-Pudlak syndrome (HPS; MIM 203300) is a genetically heterogeneous disorder characterized by oculocutaneous albinism, prolonged bleeding and pulmonary fibrosis due to abnormal vesicle trafficking to lysosomes and related organelles, such as melanosomes and platelet dense granules. In mice, at least 16 loci are associated with HPS, including sandy (sdy; ref. 7). Here we show that the sdy mutant mouse expresses no dysbindin protein owing to a deletion in the gene Dtnbp1 (encoding dysbindin) and that mutation of the human ortholog DTNBP1 causes a novel form of HPS called HPS-7. Dysbindin is a ubiquitously expressed protein that binds to alpha- and beta-dystrobrevins, components of the dystrophin-associated protein complex (DPC) in both muscle and nonmuscle cells. We also show that dysbindin is a component of the biogenesis of lysosome-related organelles complex 1 (BLOC-1; refs. 9-11), which regulates trafficking to lysosome-related organelles and includes the proteins pallidin, muted and cappuccino, which are associated with HPS in mice. These findings show that BLOC-1 is important in producing the HPS phenotype in humans, indicate that dysbindin has a role in the biogenesis of lysosome-related organelles and identify unexpected interactions between components of DPC and BLOC-1.

Ru2 and Ru encode mouse orthologs of the genes mutated in human Hermansky-Pudlak syndrome types 5 and 6.

Hermansky-Pudlak syndrome (HPS) is a genetically heterogeneous disease involving abnormalities of melanosomes, platelet dense granules and lysosomes. Here we have used positional candidate and transgenic rescue approaches to identify the genes mutated in ruby-eye 2 and ruby-eye mice (ru2 and ru, respectively), two 'mimic' mouse models of HPS. We also show that these genes are orthologs of the genes mutated in individuals with HPS types 5 and 6, respectively, and that their protein products directly interact. Both genes are previously unknown and are found only in higher eukaryotes, and together represent a new class of genes that have evolved in higher organisms to govern the synthesis of highly specialized lysosome-related organelles.

Cell-specific abnormal prenylation of Rab proteins in platelets and melanocytes of the gunmetal mouse.

The mutant gunmetal mouse exhibits reduced rates of platelet synthesis, abnormalities of platelet alpha and dense granules and hypopigmentation. Several of these features resemble those of human alpha/delta platelet storage pool disease, grey platelet syndrome and Hermansky-Pudlak syndrome. Gunmetal mice have reduced levels of Rab geranylgeranyltransferase (RabGGTase), which adds lipophilic prenyl groups to the carboxyl terminus of Rab proteins. The degree of prenylation and the subcellular distribution of several Rab proteins were evaluated in mutant platelets, melanocytes and other tissues. Significant deficits in prenylation and membrane binding of most Rabs were observed in platelets and melanocytes. In contrast, minimal alterations in Rab prenylation were apparent in several other gunmetal tissues despite the fact that RabGGTase activity was equally diminished in these tissues. The mutant tissue-specific effects are probably due to increased concentrations of Rab proteins in platelets and melanocytes. These experiments show that Rab proteins are differentially sensitive to levels of RabGGTase activity and that normal platelet synthesis, platelet organelle function and normal pigmentation are highly sensitive to the degree of prenylation and membrane association of Rab proteins. Further, the tissue-specific effects of the gunmetal mutation suggest that RabGGTase is a potential target for therapy of thrombocytosis.