High germline mutation rates, but not extreme population outbreaks, influence genetic diversity in a keystone coral predator.

Lewontin's paradox, the observation that levels of genetic diversity (π) do not scale linearly with census population size (Nc) variation, is an evolutionary conundrum. The most extreme mismatches between π and Nc are found for highly abundant marine invertebrates. Yet, the influences of new mutations on π relative to extrinsic processes such as Nc fluctuations are unknown. Here, we provide the first germline mutation rate (µ) estimate for a marine invertebrate in corallivorous crown-of-thorns sea stars (Acanthaster cf. solaris). We use high-coverage whole-genome sequencing of 14 parent-offspring trios alongside empirical estimates of Nc in Australia's Great Barrier Reef to jointly examine the determinants of π in populations undergoing extreme Nc fluctuations. The A. cf. solaris mean µ was 9.13 x 10-09 mutations per-site per-generation (95% CI: 6.51 x 10-09 to 1.18 x 10-08), exceeding estimates for other invertebrates and showing greater concordance with vertebrate mutation rates. Lower-than-expected Ne (~70,000-180,000) and low Ne/Nc values (0.0047-0.048) indicated weak influences of population outbreaks on long-term π. Our findings are consistent with elevated µ evolving in response to reduced Ne and generation time length, with important implications for explaining high mutational loads and the determinants of genetic diversity in marine invertebrate taxa.

Melanoma y embarazo / Melanoma and pregnancy

RESUMEN El melanoma cutáneo es un tumor maligno que deriva de los melanocitos. Es el segundo cáncer en orden de frecuencia en mujeres de edad fértil, y por consiguiente, representa uno de los tipos de cáncer más frecuentes diagnosticados durante el embarazo. Se presentó una paciente embarazada de 32,5 semanas de edad gestacional, con cambios clínicos a nivel de un nevo preexistente. Se realizaron una dermatoscopia, la exéresis y la biopsia de la lesión, con diagnóstico histopatológico de melanoma maligno melanocítico nodular.

ABSTRACT Cutaneous melanoma is a malignant tumor derived from melanocytes. It is the second cancer in order of frequency in women of childbearing age, and therefore represents one of the most frequent types of cancer diagnosed during pregnancy. We present a 32.5-week gestational age pregnant patient with clinical changes at the level of a pre-existing nevus. A dermoscopy, exeresis, and biopsy of the lesion were performed, with histopathological diagnosis of nodular melanocytic malignant melanoma.

Microhongos asociados a semillas de soja procedentes de la provincia del Chaco, Argentina / Microfungi associated to soja seeds from Chaco Province, Argentina

La semilla de soja es portadora de microorganismos que pueden afectar su viabilidad y la cantidad y/o calidad industrial de la producción. Mediante el método del papel de filtro se analizaron semillas de 11 cultivares procedentes de 3 localidades de la provincia de Chaco (200 semillas de cada cultivar). Se aislaron 11 taxa fúngicos, representados principalmente Cercospora kikuchii (15 por ciento), Macrophomina phaseolina (15 por ciento), Colletotrichum truncatum (12 por ciento), Phomopsis sp. (12 por ciento) y Alternaria sp. (5 por ciento). Algunos de los organismos aislados son fitopatógenos que causan enfermedades de importancia económica en cultivo de soja de la región.