Tyrosinase is the rate-limiting enzyme for the production of melanin pigmentation. In the mouse and other animals, homozygous null mutations in the Tyrosinase gene (Tyr) result in the absence of ...pigmentation, i.e. albinism. Here we used the CRISPR/Cas9 system to generate mono- and bi-allelic null mutations in the Tyr locus by zygote injection of two single-guide and Cas9 RNAs. Injection into C57BL/6N wild-type embryos resulted in one completely albino founder carrying two different Tyr mutations. In addition, three pigmentation mosaics and fully pigmented littermates were obtained that transmitted new mutant Tyr alleles to progeny in test crosses with albinos. Injection into Tyr heterozygous (B6CBAF1/J×FVB/NJ) zygotes resulted in the generation of numerous albinos and also mice with a graded range of albino mosaicism. Deep sequencing revealed that the majority of the albinos and the mosaics had more than two new mutant alleles. These visual phenotypes and molecular genotypes highlight the somatic mosaicism and allele complexity in founders that occurs for targeted genes during CRISPR/Cas9-mediated mutagenesis by zygote injection in mice.
•CRISPR/Cas was used to mutate the Tyr locus of mice by RNA injection.•Completely albino and a wide range of pigmentation mosaic founders were generated.•Deep sequencing showed that most founders had >2 new mutant alleles.•Germline transmission of the mutant alleles was demonstrated.
Seabed reflection and scattering measurements were conducted at the New England Mud Patch to better understand the acoustic properties of fine-grained (muddy) sediments. The measurement philosophy ...and the measurements themselves are summarized. In addition, geoacoustic information accessed directly from the data in the time and frequency domains is presented. The main result is the existence of an angle of intromission. This observation proves that the mud sound speed is less than that of the water and yields a sediment sound speed ratio 0.9865 with outer bounds {0.985 0.989}. Another result is the observation of strong scattered arrivals from within the mud volume at/near normal incidence but not at low grazing angles. These are likely due to anisotropic sediment heterogeneities with a large horizontal to vertical scale. Evidence is also presented for a highly heterogeneous mud-sand horizon with lateral variability down to scales of order meters. Finally, the reflection measurements successfully capture Bragg interference patterns. Their importance is their substantial geoacoustic information content, which can be accessed by several inversion methods.
Sperm competition is often envisaged as a raffle where differences in sperm quality "load" the raffle in favor of the male with the higher quality sperm. Sperm quality, however, is a complex trait, ...and the effects of its various components on the outcome of sperm competition are likely to depend upon their role in sperm transport, storage, and fertilization. Here, I use artificial insemination to assess the relationships between sperm viability, velocity, and storage on siring success in the swordtail Xiphophorus nigrensis (Teleostei: Poeciliidae), an internally fertilized fish with alternative reproductive tactics. Males with greater sperm viability sired more offspring than their rival, as predicted if the number of fertilization-capable sperm influences sperm competition in a numerical raffle. In contrast, males with faster swimming sperm sired fewer offspring, but only when sperm were stored prior to fertilization. Faster swimming sperm were thus a liability following sperm storage, suggesting a trade-off between sperm velocity and longevity in vivo. These results provide experimental evidence that the sign and magnitude can differ among components of sperm quality depending upon the mechanisms that mediate their effects.
Abstract
Indigenous Knowledge (IK) is increasingly involved in the contemporary management of natural resources. Tribal wildlife management programs in the United States may be uniquely positioned to ...effectively and ethically integrate their IK. While a narrow focus on the body of IK and a particular management activity may suffice for project‐level integration efforts, herein we consider how IK integration at the programmatic level may be best supported. We propose a holistic conceptual framework of preconditions including sovereignty, the North American Model management, funding, cultural resources, stakeholder support, and programmatic leadership. We assess the current status and common challenges with each precondition and illustrate their potential roles for a more lasting and pervasive integration of IK into tribal wildlife management programs.
To explore landscape genomics at the range limit of an obligate mutualism, we use genotyping‐by‐sequencing (ddRADseq) to quantify population structure and the effect of host–symbiont interactions ...between the northernmost fungus‐farming leafcutter ant Atta texana and its two main types of cultivated fungus. Genome‐wide differentiation between ants associated with either of the two fungal types is of the same order of magnitude as differentiation associated with temperature and precipitation across the ant's entire range, suggesting that specific ant–fungus genome–genome combinations may have been favoured by selection. For the ant hosts, we found a broad cline of genetic structure across the range, and a reduction of genetic diversity along the axis of range expansion towards the range margin. This population‐genetic structure was concordant between the ants and one cultivar type (M‐fungi, concordant clines) but discordant for the other cultivar type (T‐fungi). Discordance in population‐genetic structures between ant hosts and a fungal symbiont is surprising because the ant farmers codisperse with their vertically transmitted fungal symbionts. Discordance implies that (a) the fungi disperse also through between‐nest horizontal transfer or other unknown mechanisms, and (b) genetic drift and gene flow can differ in magnitude between each partner and between different ant–fungus combinations. Together, these findings imply that variation in the strength of drift and gene flow experienced by each mutualistic partner affects adaptation to environmental stress at the range margin, and genome–genome interactions between host and symbiont influence adaptive genetic differentiation of the host during range evolution in this obligate mutualism.
Shark finning is prohibited in many countries, but high prices for fins from the Asian market help maintain the international black-market and poaching. Traditional shark fin bans fail to recognize ...that the main driver of fin exploitation is linked to cultural beliefs about sharks in traditional Chinese culture. Therefore, shark finning should be addressed considering the social science approach as part of the fishery management scheme. This paper investigates the cultural significance of sharks in traditional Chinese and Hawaiian cultures, as valuable examples of how specific differences in cultural beliefs can drive individuals’ attitudes toward the property of shark finning. We suggest the use of a social science approach that can be useful in the design of successful education campaigns to help change individuals’ attitudes toward shark fin consumption. Finally, alternative management strategies for commercial fishers are provided to maintain self-sustainability of local coastal communities.
Dietary polyphenols promote memory in models of sleep deprivation (SD), stress, and neurodegeneration. The biological properties of dietary polyphenols greatly depend upon the bioavailability of ...their phenolic metabolites derivatives, which are modulated by gut microbiota. We recently demonstrated that supplementation with grape-derived bioactive dietary polyphenol preparation (BDPP) improves SD-induced cognitive impairment. This study examined the role of the gut microbiota in the ability of BDPP to prevent memory impairment in response to SD. C57BL6/J mice, treated with antibiotics mix (ABX) or BDPP or both, were sleep-deprived at the end of a fear conditioning training session and fear memory was assessed the next day. Gut microbiota composition was analyzed in fecal samples and BDPP-driven phenolic acid metabolites extraction was measured in plasma. We report that the beneficial effect of BDPP on memory in SD is attenuated by ABX-induced dysbiosis. We identified specific communities of fecal microbiota that are associated with the bioavailability of BDPP-derived phenolic acids, which in turn, are associated with memory promotion. These results suggest the gut microbiota composition significantly affects the bioavailability of phenolic acids that drive the dietary polyphenols' cognitive resilience property. Our findings provide a preclinical model with which to test the causal association of gut microbiota-polyphenols, with the ultimate goal of potential developing dietary polyphenols for the prevention/treatment of cognitive impairment.
Sexual transmission of beneficial microbes Smith, Chad C.; Mueller, Ulrich G.
Trends in ecology & evolution (Amsterdam),
08/2015, Letnik:
30, Številka:
8
Journal Article
Recenzirano
Beneficial sexually transmitted infections (STIs) are an understudied phenomenon with important implications for the evolution of cooperation and host reproductive behavior. Challenging the ...prevailing expectation that sexual transmission leads to pathogenesis, these symbionts provide new opportunities to examine how STIs might influence sexual selection and the evolution of promiscuity.
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