Surprisingly uneven distribution of the T cell receptor Vβ repertoire in wild mice

Journal ArticleHeterodimeric TCRa/Bs are made up of combinations of V D, J, and C elements. The majority of laboratory inbred mouse strains are of the VBh haplotype and have at least 20 VB genes from which to construct TCRs (1, 2); however, a number of strains have been reported to have deletions of large portions of the VB locus on chromosome 6 (3-5), and these mice must survive with a considerably reduced potential TCR repertoire

Gong method for capturing shorebirds and other ground-roosting species

Journal ArticleIn many shorebird studies it is necessary to capture adult birds. While shorebirds can often be trapped on the nest, capturing them away from the nest is usually very difficult and may require expensive equipment. After weeks of failure in our attempts to capture migrant and resident shorebirds in northern Utah marshes using a variety of mist-netting schemes, we became convinced that nighttime techniques held the most promise for success. Standard nightlighting techniques [Labisky 1968] are not easily applied in these kinds of marshes because of the heavy equipment involved. When we learned of a nightlighting method used by natives of the East Indies to obtain roosting shorebirds for market [H.E. McClure pets. comm.; see Murphy 1955f or a related technique],we decided to try it. The original method involves the teamwork of persons carrying long-handled nets with others carrying torches and still others who chant as they continuously beat on a gong.T his paper reports on our attempts to modify this into a western-style operation involving two individuals

MHC signaling during social communication

Journal ArticleThe major histocompatibility complex (MHC) has been known to play a critical role in immune recognition since the 1950s. It was a surprise, then, in the 1970s when the first report appeared indicating MHC might also function in social signaling. Since this seminal discovery, MHC signaling has been found throughout vertebrates and its known functions have expanded beyond mate choice to include a suite of behaviors from kin‑biased cooperation, parent‑progeny recognition to pregnancy block. The widespread occurrence of MHC in social signaling has revealed conserved behavioral‑genetic mechanisms that span vertebrates and includes humans. The identity of the signal's chemical constituents and the receptors responsible for the perception of the signal have remained elusive, but recent advances have enabled the identification of the key components of the behavioral circuit. In this chapter we organize recent findings from the literature and discuss them in relation to four nonmutually exclusive models wherein MHC functions as a signal of (i) individuality, (ii) relatedness, (iii) genetic compatibility and (iv) quality. We also synthesize current mechanistic studies, showing how knowledge about the molecular basis of MHC signaling can lead to elegant and informative experimental manipulations. Finally, we discuss current evidence relating to the primordial functions of the MHC, including the possibility that its role in social signaling may be ancestral to its central role in adaptive immunity

Major histocompatibility complex-dependent susceptibility to Cryptococcus neoformans in mice

Journal ArticleTo evaluate the role of major histocompatibility complex (MHC) genes in the resistance to Cryptococcus neoformans, we conducted infection experiments in MHC-congenic strains of mice. Significant MHC-dependent susceptibility differences were found among homozygotes and heterozygotes. This study is the first experimental demonstration of MHC-dependent susceptibility to C. neoformans infections in mice and indicates that MHC genes can be important in host resistance

Infection-dependent phenotypes in MHC-congenic mice are not due to MHC: can we trust congenic animals?

Journal ArticleCongenic strains of mice are assumed to differ only at a single gene or region of the genome. These mice have great importance in evaluating the function of genes. However, their utility depends on the maintenance of this true congenic nature. Although, accumulating evidence suggests that congenic strains suffer genetic divergence that could compromise interpretation of experimental results, this problem is usually ignored. During coinfection studies with Salmonella typhimurium and Theiler's murine encephalomyelitis virus (TMEV) in major histocompatibility complex (MHC)-congenic mice, we conducted the proper F2 controls and discovered significant differences between these F2 animals and MHC-genotype-matched P0 and F1 animals in weight gain and pathogen load. To systematically evaluate the apparent non-MHC differences in these mice, we infected all three generations (P0, F1 and F2) for 5 MHC genotypes (b/b, b/q and q/q as well as d/d, d/q, and q/q) with Salmonella and TMEV

Evolution of mating preferences and major histocompatibility complex genes

Journal ArticleHouse mice prefer mates genetically dissimilar at the major histocompatibility complex (MHC). The highly polymorphic MHC genes control immunological self/nonself recognition; therefore, this mating preference may function to provide "good genes" for an individual's offspring. However, the evidence for MHC-dependent mating preferences is controversial, and its function remains unclear. Here we provide a critical review of the studies on MHCdependent mating preferences in mice, sheep, and humans and the possible functions of this behavior. There are three adaptive hypotheses for MHC-dependent mating preferences. First, MHCdisassortative mating preferences produce MHC-heterozygous offspring that may have enhanced immunocompetence. Although this hypothesis is not supported by tests of single parasites, MHC heterozygotes may be resistant to multiple parasites

Consequences of self and foreign superantigen interaction with specific VB elements of the murine TCR aB

Journal ArticleThe aB T-cell receptor (TCRaB) recognizes a ligand composed of an antigen fragment complexed with a product of the major histocompatibility complex (MHC). The repertoire of receptors is limited both by the germ line of receptor variable elements and by selective events that take place during T-cell development. The current view is that the germ-line repertoire is expressed in the thymus randomly but that only those T cells bearing receptors that successfully interact with MHC molecules expressed on thymic cortical epithelial cells are allowed to mature (Bevan and Fink 1978; Zinkernagel et al. 1978; Kisielow et al. 1988; Sha et al. 1988). Furthermore, during the process of establishing tolerance to self-antigens, this positively selected population is further reduced by the deletion or inactivation of clones whose receptors continue to interact with self-antigen/MHC ligands (Kappler et al. 1987a, 1988; MacDonald et al. 1988; Pullen et al. 1988). Thus, positive and negative selections reduce expressed receptor repertoire in the periphery to a fraction of the germ-line repertoire

Major histocompatibility complex heterozygote superiority during coinfection

Journal ArticleGenes of the major histocompatibility complex (MHC) play a critical role in immune recognition, and many alleles confer susceptibility to infectious and autoimmune diseases. How these deleterious alleles persist in populations is controversial

Relationship of virulence factor expression to evolved virulence in mouse-passaged Cryptococcus neoformans lines

Journal ArticleSerial passage of Cryptococcus neoformans in mice increases virulence relative to the nonpassaged line. Postpassaged lines showed no difference in the expression of most known virulence factors, with the exception that the more virulent lines had smaller capsules in vitro. These data imply that other mechanisms of virulence remain to be discovered

Emigration behavior of Clark's Nutcracker

Journal ArticleEruptive movements of the Clark's Nutcracker (Nucifraga columbiana) were observed during the late summer and fall of 1977, 1978 and 1979 in northern Utah and adjacent states. Over 2,000 emigrating nutcrackers were seen during these periods. Eruptions began in mid to late August, about the time nutcrackers began foraging on developing conifer cones, and continued until early October. Nearly all nutcrackers traveled in small, loose flocks (x = 10.1 individuals). During 1977-1978, most emigrating nutcrackers appeared to winter in p&on-juniper woodlands of Utah and adjacent states and no nutcrackers were reported outside their normal breeding range. A northward movement of nutcrackers, presumably the same population observed emigrating southward in fall 1977, was noted in summer 1978. Evidence for breeding of nutcrackers on their wintering areas is presented. A compartmental model summarizes current knowledge on the temporal and spatial aspects of nutcracker emigration