| oviposition and incubation environmental effects on embryonic diapause in a ground cricket | maternal effects on offspring phenotype are well known in organisms inhabiting seasonal environments. mothers that perceive climatological changes indicative of winter's onset will often produce increasing numbers of offspring that enter a state of arrested morphogenesis known as 'diapause'. in this study of bivoltine allonemobius socius ground crickets, we manipulated the abiotic environment experienced by ovipositing females (i.e. maternal-oviposition environment) and that experienced by offsp ... | 1998 | 9480701 |
| a quantitative genetic analysis of phenotypic plasticity of diapause induction in the cricket allonemobius socius. | although numerous studies have indicated that diapause is heritable and phenotypically plastic, none of them has examined the quantitative genetic basis of this plasticity. in this paper we report such an analysis for egg diapause in the cricket allonemobius socius, the induction of which appears to be largely determined by the mother. we analysed the quantitative genetic basis of the phenotypically plastic response of female a. socius to age and environmental conditions. we measured the product ... | 2000 | 10762389 |
| spatio-temporal dynamics of the allonemobius fasciatus- a. socius mosaic hybrid zone: a 14-year perspective. | long-term studies of hybrid zones can provide valuable insight into a number of questions that have long attracted the attention of evolutionists. these questions range from the stability and fate of hybrid zones to the relative fitness of hybrids. in this paper we report the results of a 14-year survey of the allonemobius fasciatus-allonemobius socius hybrid zone. populations were collected intensively in 1986 and 1987 and then more sporadically through the end of the 1980s and throughout the 1 ... | 2001 | 11298974 |
| the threshold model as a general purpose normalizing transformation. | the estimation of heritabilities and genetic correlations is based on the assumption that the trait distributions are normal. when the distributions are not normal it is advisable to transform the data to produce normality. however, it is possible that no suitable transformation can be found. the purpose of the present paper is to point out that the threshold model of quantitative genetics can be used as a generalized transformation. to utilize this method it is only necessary to divide the data ... | 2001 | 11520340 |
| nuptial gifts and the evolution of male body size. | in many insect systems, males donate nuptial gifts to insure an effective copulation or as a form of paternal investment. however, if gift magnitude is both body size-limited and positively related to fitness, then the opportunity exists for the gift to promote the evolution of large male size. in the striped ground cricket, allonemobius socius, males transfer a body size-limited, somatic nuptial gift that is comprised primarily of hemolymph. to address the implications of this gift on male size ... | 2002 | 11989688 |
| female mating bias results in conflicting sex-specific offspring fitness. | indirect-benefit models of sexual selection assert that females gain heritable offspring advantages through a mating bias for males of superior genetic quality. this has generally been tested by associating a simple morphological quality indicator (for example, bird tail length) with offspring viability. however, selection acts simultaneously on many characters, limiting the ability to detect significant associations, especially if the simple indicator is weakly correlated to male fitness. furth ... | 2004 | 15129280 |
| immune suppression and the cost of reproduction in the ground cricket, allonemobius socius. | one of the most common life history trade-offs in animals is the reduction in survivorship with increasing reproductive effort. despite the prevalence of this pattern, its underlying physiological mechanisms are not well understood. here we test the hypothesis that immune suppression mediates this phenotypic trade-off by manipulating reproductive effort and measuring immune function and mortality rates in the striped ground cricket, allonemobius socius. because a. socius males provide females wi ... | 2004 | 15612291 |
| interaction between maternal effects and temperature affects diapause occurrence in the cricket allonemobius socius. | the induction of diapause can be adaptive for egg survival during unfavorable conditions, while direct development can be advantageous under favorable conditions by allowing additional generations to exploit abundant resources. therefore, the physiological capability of a female to respond to environmental cues indicative of habitat quality by producing eggs of the appropriate developmental phenotype should be under strong selection. additionally, developing embryos may alter the developmental t ... | 2006 | 16133190 |
| sexual conflict and female immune suppression in the cricket, allonemobious socius. | in many animal systems, females exhibit a localized immune response to insemination that helps defend against sexually transmitted disease. however, this response may also kill sperm, reducing a male's reproductive potential. if males could suppress this response, they may be able to increase their sperm's representation in the female's reproductive tract, thereby increasing their fitness. here we address the hypothesis that, under conditions of sperm competition, males interfere with female imm ... | 2005 | 16313464 |
| the evolutionary genetics of sexual size dimorphism in the cricket allonemobius socius. | in recent years, investigations into the evolution of sexual size dimorphism have moved from a simple single trait, single sex perspective, to the more robust view of multivariate selection acting on both males and females. however, more accurate predictions regarding selection response may be possible if some knowledge of the underlying sex-specific genetic architecture exists. in the striped ground cricket, allonemobius socius, females are the larger sex. furthermore, body size appears to be c ... | 2007 | 17473861 |
| patterns of phenotypic and genetic variation for the plasticity of diapause incidence. | phenotypic plasticity describes an organism's ability to produce multiple phenotypes in direct response to its environmental conditions. over the past 15 years empiricists have found that this plasticity frequently exhibits geographic variation and often possesses a significant heritable genetic basis. however, few studies have examined both of these aspects of plasticity simultaneously. here, we examined both the geographic and genetic variations of the plasticity for diapause incidence (the pr ... | 2007 | 17598737 |
| rapid evolution of spermathecal duct length in the allonemobius socius complex of crickets: species, population and wolbachia effects. | the three species in the allonemobius socius complex of crickets have recently diverged and radiated across north america. interestingly, the only barriers to gene flow between these species in zones of secondary contact appear to be associated with fertilization traits - e.g., conspecific sperm precedence and the ability of males to induce females to lay eggs. other traits, such as the length of female's reproductive tract, may also influence fertilization success and be associated with species ... | 2007 | 17684565 |
| the genetics of reproductive isolation: a retrospective and prospective look with comments on ground crickets. | an intriguing aspect of the current renaissance in investigations of the genetics of reproductive isolation is that it has been dominated by studies that resemble work done in the 1930s, 1940s, and 1950s. the dominant model organism (drosophila), research approaches, and traits of interest (sterility and inviability of hybrids) all harken back to this earlier era. herein, we explore the factors that led to a rebirth of interest in the genetics of reproductive isolation and to the adoption of the ... | 2002 | 18707372 |
| geographic distributions of idh-1 alleles in a cricket are linked to differential enzyme kinetic performance across thermal environments. | geographic clines within species are often interpreted as evidence of adaptation to varying environmental conditions. however, clines can also result from genetic drift, and these competing hypotheses must therefore be tested empirically. the striped ground cricket, allonemobius socius, is widely-distributed in the eastern united states, and clines have been documented in both life-history traits and genetic alleles. one clinally-distributed locus, isocitrate dehydrogenase (idh-1), has been show ... | 2009 | 19460149 |
| decoupling development and energy flow during embryonic diapause in the cricket, allonemobius socius. | respiration rate increases 6.3-fold during 15 days of post-oviposition development in embryos of the southern ground cricket, allonemobius socius. this ontogenetic increase in metabolism of non-diapause insects is blocked during diapause, such that metabolic rate is only 36% of the rate measured for 15 days developing embryos. surprisingly, however, there is not an acute metabolic depression during diapause entry at the point when developmental ceases (4-5 days post-oviposition), as measured by ... | 2009 | 19525433 |
| embryonic diapause highlighted by differential expression of mrnas for ecdysteroidogenesis, transcription and lipid sparing in the cricket allonemobius socius. | embryos of the ground cricket, allonemobius socius, enter diapause 4-5 days post-oviposition and overwinter in this dormant state that is characterized by developmental arrest. suppressive subtractive hybridization and quantitative real-time pcr reveal eight candidate genes in pre-diapause embryos that show promise as regulators of diapause entry, when compared with embryos not destined for diapause. identifications are based both on the magnitude/consistency of differential mrna abundances and ... | 2009 | 19525434 |
| identification, rnai knockdown, and functional analysis of an ejaculate protein that mediates a postmating, prezygotic phenotype in a cricket. | postmating, prezygotic phenotypes, especially those that underlie reproductive isolation between closely related species, have been a central focus of evolutionary biologists over the past two decades. such phenotypes are thought to evolve rapidly and be nearly ubiquitous among sexually reproducing eukaryotes where females mate with multiple partners. because these phenotypes represent interplay between the male ejaculate and female reproductive tract, they are fertile ground for reproductive se ... | 2009 | 19851502 |
| relative effects of juvenile and adult environmental factors on mate attraction and recognition in the cricket, allonemobius socius. | finding a mate is a fundamental aspect of sexual reproduction. to this end, specific-mate recognition systems (smrs) have evolved that facilitate copulation between producers of the mating signal and their opposite-sex responders. environmental variation, however, may compromise the efficiency with which smrs operate. in this study, the degree to which seasonal climate experienced during juvenile and adult life-cycle stages affects the smrs of a cricket, allonemobius socius (scudder) (orthoptera ... | 2010 | 20673114 |