23 research outputs found
Parnassius apollo nevadensis: identification of recent population structure and source–sink dynamics
Population persistence depends in many cases on gene flow between local populations. Parnassius apollo nevadensis is an endemic subspecies of Apollo butterfly in the Sierra Nevada (southern Spain), whose populations are distributed in discrete patches at altitudes between 1850 and 2700 m. In this paper, we use 13 microsatellite loci to examine the genetic structure of this P. apollo subspecies. We revealed both a strong pattern of isolation by distance (which was stronger when calculated with realistic travel distances that accounted for topography) and source–sink dynamics. The observed population genetic structure is consistent with strongly asymmetrical gene flow, leading to constant directional migration and differential connectivity among the populations. The apparently contradictory results from the clustering algorithms (Structure and Geneland) are also consistent with a recent (<100 ya) reduction in the distribution range. The results point to global warming as a possible cause of this reduction, as in other populations of this species. We identify some natural and anthropogenic barriers to gene flow that may be the cause of the recent population structure and source–sink dynamics
Resultados de observaciones de cometas
Hemos querido presentar en esta reunión los resultados de observaciones de algunos cometas, efectuadas en el período comprendido entre los años 1974-1981 en la Estación Astronómica de Altura "El Leóncito", o sea a partir del momento en que este Observatorio pasa a depender del Observatorio Astronómico "Félix Aguilar" de la Universidad Nacional de San Juan. Las observaciones se realizaron con el Astrógrafo Doble de 0,50 m, usando placas Kodak con emulsiones 103a-0 y 103a-G.Asociación Argentina de Astronomí
Avanços recentes em nutrição de larvas de peixes
Os requisitos nutricionais de larvas de peixes são ainda mal compreendidos, o que leva a altas mortalidades
e problemas de qualidade no seu cultivo. Este trabalho pretende fazer uma revisão de novas metodologias de investigação, tais
como estudos com marcadores, genómica populacional, programação nutricional, génomica e proteómica funcionais, e
fornecer ainda alguns exemplos das utilizações presentes e perspectivas futuras em estudos de nutrição de larvas de peixes
The Mutational Landscape of Circulating Tumor Cells in Multiple Myeloma
The development of sensitive and non-invasive
‘‘liquid biopsies’’ presents new opportunities for
longitudinal monitoring of tumor dissemination and
clonal evolution. The number of circulating tumor
cells (CTCs) is prognostic in multiple myeloma
(MM), but there is little information on their genetic
features. Here, we have analyzed the genomic landscape
of CTCs from 29 MM patients, including eight
cases with matched/paired bone marrow (BM) tumor
cells. Our results show that 100% of clonal mutations
in patient BM were detected in CTCs and that 99% of
clonal mutations in CTCs were present in BM MM.
These include typical driver mutations in MM such
as in KRAS, NRAS, or BRAF. These data suggest
that BM and CTC samples have similar clonal structures,
as discordances between the two were
restricted to subclonal mutations. Accordingly, our
results pave the way for potentially less invasive
mutation screening of MM patients through characterization
of CTCs
Cis- and trans-regulation in X inactivation
Female mammalian cells compensate dosage of X-linked gene expression through the inactivation of one of their two X chromosomes. X chromosome inactivation (XCI) in eutherians is dependent on the non-coding RNA Xist that is up-regulated from the future inactive X chromosome, coating it and recruiting factors involved in silencing and altering its chromatin state. Xist lies within the X-inactivation center (Xic), a region on the X that is required for XCI, and is regulated in cis by elements on the X chromosome and in trans by diffusible factors. In this review, we summarize the latest results in cis- and trans-regulation of the Xic. We discuss how the organization of the Xic in topologically associating domains is important for XCI (cis-regulation) and how proteins in the pluripotent state and upon development or differentiation of embryonic stem cells control proper inactivation of one X chromosome (trans-regulation)
Nuevo listado de estrellas rojas rojas y nebulosas planetarias
Presentamos en esta Reunión las posiciones inéditas de un grupo de Estrellas Rojas y Nebulosas Planetarias, descubiertas en la Estación Astronómica de Altura “El Leóncito" con el Astrógrafo Doble de 20" y utilizando placas con emulsión 103 a 0 y 103 a G, con las cuales vamos a realizar un catálogo.Asociación Argentina de Astronomí