Integrating natural and sexual selection across the biphasic life cycle

An alternation between diploid and haploid phases is universal among sexual eukaryotes. Across this biphasic cycle, natural selection and sexual selection occur in both phases. Together, these four stages of selection act on the phenotypes of individuals and influence the evolutionary trajectories of populations, but are rarely studied holistically. Here, we provide a conceptual framework that transcends taxonomic groups, and unifies the entire selection landscape within and across the diploid and haploid phases. Our synthesis produces six direct links among four selection stages, and from this we define four types of parental effect. We argue that knowledge of the complex and intertwined opportunities for selection within biphasic life cycles will offer clearer insights into key ecological and evolutionary processes, with benefits to applied science.

Nonsense-mediated decay controls the reactivation of the oncogenic herpesviruses EBV and KSHV

The oncogenic human herpesviruses Epstein–Barr virus (EBV) and Kaposi’s sarcoma-associated herpesvirus (KSHV) are the causative agents of multiple malignancies. A hallmark of herpesviruses is their biphasic life cycle consisting of latent and lytic infection. In this study, we identified that cellular nonsense-mediated decay (NMD), an evolutionarily conserved RNA degradation pathway, critically regulates the latent-to-lytic switch of EBV and KSHV infection. The NMD machinery suppresses EBV and KSHV Rta transactivator expression and promotes maintenance of viral latency by targeting the viral polycistronic transactivator transcripts for degradation through the recognition of features in their 3′ UTRs. Treatment with a small-molecule NMD inhibitor potently induced reactivation in a variety of EBV- and KSHV-infected cell types. In conclusion, our results identify NMD as an important host process that controls oncogenic herpesvirus reactivation, which may be targeted for the therapeutic induction of lytic reactivation and the eradication of tumor cells.

Settlement and Metamorphosis in Barnacles and Decapods

Settlement and metamorphosis are two crucial processes in organisms with a biphasic life cycle, forming the link between the pelagic larva and benthic juvenile-adult. In general, these processes occur during the final larval stage. Among crustaceans, settlement behavior and the cues that trigger settlement and metamorphosis have been studied in greater depth in barnacles than in decapods, likely a result of the former losing the ability to move after they join the benthic juvenile-adult population, undergoing metamorphosis. Both barnacles and decapods respond to different environmental cues associated with the adult habitat, such as substratum, biofilm, and the presence of conspecifics. In the absence of cues, larvae can delay their metamorphosis for a period of time. This ability to prolong the development can be advantageous because it increases the probability of settling in a suitable habitat. However, delayed metamorphosis has also associated costs (e.g., smaller size, lower growth rate, and higher mortality), which may be carried over to subsequent development stages, with consequences for recruitment.

Ambiguous skin ulcer on the ear pinna

Cutaneous leishmaniasis (CL) is a parasitic disease which has a biphasic life cycle; infection by promastigotes from the sandfly reaches a wound where it is phagocytosed by macrophages, producing the amastigote (the Leishmania donovani body) in the host. A protozoan parasite transmitted by the phlebotomous sandfly causes human leishmaniasis. Cutaneous forms include classical cutaneous, mucocutaneous and post-kala-azar dermal leishmaniasis. It affects c. 300 million individuals in more than 90 nations around the globe. The cutaneous form in the Old World is caused at low altitudes mainly by L. major (which has an animal reservoir, rodents such as mouse) and in swampy regions and high altitudes by L. tropica (which has no animal reservoir). L. aethiopica and L. major lead to disseminated ulcers in Saudi Arabia, Yemen, Iraq, Iran, Pakistan, India, Tunisia, Sudan and Ethiopia, whose main electrophoretic isozyme pattern Zymodeme in Saudi Arabia is LON-4.

MENGENAL MAKROALGA Turbinaria DAN PEMANFAATANNYA

KNOWING MACROALGAE Turbinaria AND THEIR USAGES. Turbinaria is a member of brown macroalgae that can be found in almost all Indonesian waters. Turbinaria is often regarded as Sargassum because they have a similar morphology and both belong to the Family Sargassaceae. There are 35 species of Turbinaria in the world and 11 of which can be found in Indonesia. Turbinaria conoides, T. decurrens and T. ornata are the most common ones in Indonesian waters. Turbinaria grows on rocky intertidal coastlines, tidepools and reef flats. The life cycle of Turbinaria occurs through alternations between sexual and asexual. Their biphasic life cycle contains gametophytes and sprorophytes. In their sexual reproduction, sporophytes resulted from the germination of zygotes formed by fusion (fertilization) of male and female gametes. Asexual spores develop from both sporophytes and gametophytes. Turbinaria was commonly used as a source of alginate, fucoidan and other bioactive polysaccharides (antioxidant, anticancer, antibacterial, anticoagulant, antiploriferative and antivirus activities).

Ecophysiology of Amphibians: Information for Best Mechanistic Models

Several amphibian lineages epitomize the faunal biodiversity crises, with numerous reports of population declines and extinctions worldwide. Predicting how such lineages will cope with environmental changes is an urgent challenge for biologists. A promising framework for this involves mechanistic modeling, which integrates organismal ecophysiological features and ecological models as a means to establish causal and consequential relationships of species with their physical environment. Solid frameworks built for other tetrapods (e.g., lizards) have proved successful in this context, but its extension to amphibians requires care. First, the natural history of amphibians is distinct within tetrapods, for it includes a biphasic life cycle that undergoes major habitat transitions and changes in sensitivity to environmental factors. Second, the accumulated data on amphibian ecophysiology is not nearly as expressive, is heavily biased towards adult lifeforms of few non-tropical lineages, and overlook the importance of hydrothermal relationships. Thus, we argue that critical usage and improvement in the available data is essential for enhancing the power of mechanistic modeling from the physiological ecology of amphibians. We highlight the complexity of ecophysiological variables and the need for understanding the natural history of the group under study and indicate directions deemed crucial to attaining steady progress in this field.