RESUMO
Poecilogony is a type of reproduction in which a species produces different types of larvae. Boccardia wellingtonensis, is a poecilogonous polychaete with females producing planktotrophic and adelphophagic larvae, in addition to nurse eggs, in the same capsule that differ in feeding behavior. It is still unclear why planktotrophs do not feed on nurse eggs during the intracapsular development and arrest its growth, while adelphophagic larvae consume nurse eggs and planktotrophic larvae inside the capsule, hatching as advance larvae or as juveniles. Here we characterized the expression of selected miRNAs from these two types of larvae and from adults in order to begin to understand the molecular mechanisms that regulate expression in this type of poecilogony. Results showed that adults and pre-hatching adelphophagic larvae have high levels of expression of miR-125, miR-87a and let-7, while adelphophages at early developmental stage had low levels of expression of miR-87b. Planktotrophic larvae showed low expression level of let-7. This work represents the first step in understanding the role of miRNAs in the development of different larval types in a poecilogonous species. We also propose to B. wellingtonensis as an interesting biological model to study the evolution of larval modes and reproductive strategies of marine invertebrates.
Assuntos
Expressão Gênica , MicroRNAs/genética , Poliquetos/genética , Animais , Comportamento Alimentar , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , MicroRNAs/metabolismo , Poliquetos/crescimento & desenvolvimento , Poliquetos/fisiologia , ReproduçãoRESUMO
By examining material collected in the Sierra Nevada de Santa Marta (Department of Magdalena, Colombia), the authors report a new record for the entire South America, Doryphoribius gibber Beasley & Pilato, 1987, and two species new to science, Paramacrobiotus sagani sp. nov., and Doryphoribius rosane sp. nov., are described. Paramacrobiotus sagani sp. nov. belongs to the richtersi group, vanescens subgroup (by having sculptured egg areolae) and is characterized by a peculiar cuticular granulation, trunco-conical egg processes with cylindrical indented apices, and other more detailed cha-racters both qualitative and metric; by the unique combination of characters, it differs from all the other known species of the genus. Doryphoribius rosanae sp. nov. is characterized by reticulated dorsal cuticle with gibbosities (formula IX:4-6-2-6-2-6-4-2-2), two macroplacoids in the pharynx without microplacoid or septulum, and large, stout claws without "free" accessory points but with lunules. It differs from all the other Doryphoribius species with gibbosities by having a unique formula, as well as other more detailed characters. Thanks to this contribution, the number of tardigrade species known for Colombia increases from 52 to 55.
Assuntos
Tardígrados , Animais , Colômbia , América do SulRESUMO
A new species, Milnesium kogui sp. nov. is described from the Sierra Nevada de Santa Marta, Colombia. The new species belongs to the tardigradum group and is most similar, by the claw configuration [2-2]-[2-2], to Milnesium dujiangensis and Milnesium katarzynae. Milnesium kogui sp. nov. differs from M. dujiangensis mainly by the presence of primary branches on all legs and from M. katarzynae by the absence of dorsal sculpture. Additionally, in this paper we present a list of all Milnesium species recorded in Colombia including Milnesium cf. barbadosense Meyer & Hinton, 2012 and M. brachyungue Binda & Pilato, 1990, new additions to the recorded fauna of Colombia.