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Current Biology : CB Jun 2024Host reproduction can be manipulated by bacterial symbionts in various ways. Parthenogenesis induction is the most effective type of reproduction manipulation by...
Host reproduction can be manipulated by bacterial symbionts in various ways. Parthenogenesis induction is the most effective type of reproduction manipulation by symbionts for their transmission. Insect sex is determined by regulation of doublesex (dsx) splicing through transformer2 (tra2) and transformer (tra) interaction. Although parthenogenesis induction by symbionts has been studied since the 1970s, its underlying molecular mechanism is unknown. Here we identify a Wolbachia parthenogenesis-induction feminization factor gene (piff) that targets sex-determining genes and causes female-producing parthenogenesis in the haplodiploid parasitoid Encarsia formosa. We found that Wolbachia elimination repressed expression of female-specific dsx and enhanced expression of male-specific dsx, which led to the production of wasp haploid male offspring. Furthermore, we found that E. formosa tra is truncated and non-functional, and Wolbachia has a functional tra homolog, termed piff, with an insect origin. Wolbachia PIFF can colocalize and interact with wasp TRA2. Moreover, Wolbachia piff has coordinated expression with tra2 and dsx of E. formosa. Our results demonstrate the bacterial symbiont Wolbachia has acquired an insect gene to manipulate the host sex determination cascade and induce parthenogenesis in wasps. This study reveals insect-to-bacteria horizontal gene transfer drives the evolution of animal sex determination systems, elucidating a striking mechanism of insect-microbe symbiosis.
Topics: Animals; Wolbachia; Wasps; Symbiosis; Female; Male; Gene Transfer, Horizontal; Parthenogenesis; Insect Proteins; Sex Determination Processes
PubMed: 38692276
DOI: 10.1016/j.cub.2024.04.035 -
Proceedings of the National Academy of... Nov 2023A female-biased sex ratio is considered advantageous for the cytoplasmic elements that inhabit sexually reproducing organisms. There are numerous examples of bacterial...
A female-biased sex ratio is considered advantageous for the cytoplasmic elements that inhabit sexually reproducing organisms. There are numerous examples of bacterial symbionts in the arthropod cytoplasm that bias the host sex ratio toward females through various means, including feminization and male killing. Recently, maternally inherited RNA viruses belonging to the family Partitiviridae were found to cause male killing in moths and flies, but it was unknown whether male-killing viruses were restricted to Partitiviridae or could be found in other taxa. Here, we provide compelling evidence that a maternally inherited RNA virus, Spodoptera litura male-killing virus (SlMKV), selectively kills male embryos of the tobacco caterpillar , resulting in all-female broods. SlMKV injected into uninfected can also be inherited maternally and causes male killing. SlMKV has five genomic segments encoding seven open reading frames, has no homolog of known male-killing genes, and belongs to an unclassified group of arthropod-specific viruses closely related to Tolivirales. When transinfected into larvae, both male and female recipients allow SlMKV to proliferate, but only males die at the pupal stage. The viral RNA levels in embryonic and pupal male killing suggest that the mechanism of male killing involves the constitutive expression of viral products that are specifically lethal to males, rather than the male-specific expression of viral products. Our results, together with recent findings on male-killing partiti-like viruses, suggest that diverse viruses in arthropods tend to acquire male killing independently and that such viruses may be important components of intragenomic conflict in arthropods.
Topics: Female; Male; Animals; Moths; Spodoptera; Arthropods; Larva; Viruses
PubMed: 37931114
DOI: 10.1073/pnas.2312124120 -
Gland Surgery Jul 2023Gender-affirming surgery (GAS), including breast feminization, is requested and performed with increasing frequency. Transgender women may seek chest feminization... (Review)
Review
Gender-affirming surgery (GAS), including breast feminization, is requested and performed with increasing frequency. Transgender women may seek chest feminization surgery to address gender dysphoria, and such procedures have been shown to increase psychosocial and sexual well-being. Despite the potential effects of hormone therapy and androgen blockade on breast development, the results of glandular growth in adult transgender women are typically disappointing and are often inadequate to achieve the patient's goals. When evaluating options for breast construction, an implant-based approach meets the needs of most patients. However, patient choice, implant complications, acquired and congenital alterations of chest anatomy and the unique challenges of feminizing a natal male chest occasionally require consideration of other options. We review the few cases of gender-affirming breast reconstruction using autologous tissue published in the literature and summarize the senior author's approach and technique. We also review two cases of autologous chest feminization by the senior author. Ultimately, while implant-based reconstruction should continue to be the default procedure and offered to the majority of patients, several factors need to be considered when determining the optimal approach to breast feminization for a given patient. In patients with congenital or acquired deformities or a variety of factors where a reasonable outcome cannot be achieved with implants, autologous reconstruction should remain an option.
PubMed: 37727344
DOI: 10.21037/gs-23-133 -
Frontiers in Veterinary Science 2023Over the past three decades, the veterinary profession has faced a cultural shift towards postspeciesism that requires a reassessment of the foundations of the existing...
Over the past three decades, the veterinary profession has faced a cultural shift towards postspeciesism that requires a reassessment of the foundations of the existing distinctions between human and non-human animals proclaimed by the speciesism paradigm, which represents institutionalized discrimination against species and recognizes only the subjectivity of humans. Based on ethnographic observations in anthropological fieldwork and using speciesism/postspeciesism distinction, we aimed to explain the main causes of small animal practitioners' work-related stress and apply humanistic knowledge to recommend ways to alleviate the negative effects of the work environment. The explanatory model of disease, illness, and sickness, the example of the concept of family, and the circumstances of the feminization of the veterinary profession are discussed to illustrate the divergence between speciesist naturalistic veterinary knowledge and the postspeciesist cultural framework and its consequences. By failing to accommodate the changing values towards animals and by failing to challenge the anthropocentric hierarchy of values, the speciesist rationale of the veterinary profession contributes to many of the problems faced by practicing veterinarians. The incorporation of a modern moral-philosophical mindset towards animals may not even be possible because veterinary science is subject to a paradigm that is irreversibly tied to institutional discrimination against species and defies reflection on veterinary science itself. However, the veterinary profession has a privileged position in establishing an alternative ontological thinking and an alternative conception of "animal life." Anthropological knowledge was applied to anticipate further intervention of social and cultural sciences in the problems of small animal practitioners. Rather than further diversifying and increasing expectations towards veterinarians by expecting them to acquire additional skills, we propose another practitioner who can support, mediate, and enhance veterinary performance - the cultural anthropologist. With their deep knowledge of cultural differences and social dynamics, they can collaborate with veterinarians to act as a liaison between cultures, paradigms, and species.
PubMed: 37601748
DOI: 10.3389/fvets.2023.1202606