This work describes the construction and characterization of a sequence characterized amplified DNA region (SCAR DNA), designated OmyP9, that was derived from a RAPD marker associated with the sex chromosomes in rainbow trout. A RsaI restriction fragment length polymorphism in OmyP9 identifies variants A, B and C. We found six OmyP9 variant phenotypes - A, B, C, AB, BC and ABC, in 186 individuals of seven different rainbow trout strains. The patterns of inheritance of OmyP9 in 139 fingerlings from 10 crosses of three strains of rainbow trout were studied. The males had a greater representation of the A variant (93.3%) suggesting an association with the Y chromosome. All male fingerlings analysed inherited the A variant from their male parents. These results support the hypothesis that OmyP9 is located on the sex chromosomes of rainbow trout, and that for the males studied the A variant is located on the Y chromosome in a region close to sex determinants and/or in a sector where the genetic recombination between X and Y is restricted. The present evidence also supports our previous hypothesis that OmyP9 is organized as a tandem repeated sequence in the sex chromosomes of rainbow trout. We feel that the OmyP9 RsaI marker can be used for sex identification in crosses where it is possible to determine the phenotype of the parents.

Background: The main objective of this investigation was to determine the incidence of infectious postoperative complications in oral surgery. Material and Methods: A observational and descriptive study was developed, with the use of prospective registry of the patients admitted for oral surgery at the San Borja Arriarán Hospital Complex during twelve months observation period (April 2017 to March 2018). Results: The sample consisted of 532 patients undergoing surgical procedures of oral surgery and 19 cases of infectious postoperative complications. The incidence of complications reached 3,57% and it was observed predominantly in exodontic type interventions. The most commonly observed complication was dry socket, reaching 2,5% of third molar surgeries and 3,7% of extractions of other teeth. Other postoperative complication were 7 cases of facial spaces abscesses, also observed predominantly in exodontic type interventions. Conclusions: The results were similar to those reported in the literature both in their frequency and in the type of complication.

This study describes the genetic structure of five naturalized populations of brown trout in southern Chile using allozyme and microsatellite markers to establish levels of intra‐ and interpopulation genetic variability and divergence. Fourteen enzymatic systems were used comprising 20 loci and three microsatellite loci specific to brown trout. The genetic variability values (allozymes, P=20–35%, average=27%, HO=0.118–0.160, average=0.141; microsatellites, P=33.3–100%, average=66.66%, HO=0.202–0.274, average=0.229) are similar to values described in other naturalized populations of brown trout present in Chile, but higher than those observed in European populations of this species. Values of total genetic diversity (HT) (allozymes=0.1216 and microsatellites=0.3504) and relative genetic divergence (GST) (allozymes=9.5% and microsatellites=15%) were also similar to the results obtained in previous studies of Chilean populations of brown trout. These values, when compared with those obtained in Europe, proved to be similar for HT but lower for GST. The low interpopulational genetic differentiation was in accordance with the small genetic distance observed between the populations analysed (D Nei=0.004–0.025). On the other hand, the high frequency of one of the two alternative alleles of the phylogeographic marker locus LDH‐5* in the populations analysed (LDH‐5*90>0.84) would indicate a European origin, in particular Atlantic as opposed to Mediterranean, for the brown trout introduced into Chile. The high levels of genetic variability suggest a mixed origin for the naturalized brown trout in Chile, which could have originated either before or during the introduction process. Nevertheless, the low level of genetic differentiation between populations could reflect the short lapse of time in evolutionary terms, during which populations introduced into Chile have been exposed to different evolutionary forces, and which has not been sufficiently long to produce greater genetic differentiation between populations.

The goal of this work is to identify molecular markers associated with the sex chromosomes in rainbow trout to study the mode of sex determination mechanisms in this species. Using the RAPD assay and bulked segregant analysis, two markers were identified that generated polymorphic bands amplifying preferentially in males of the Mount Lassen and Scottish strains of rainbow trout. Chromosomal localization using fluorescent in situ hybridization of a 900 bp probe developed from one of these markers revealed a brightly defined signal on a chromosome that could morphologically be classified as the Y chromosome.

With the aim of characterizing the sex chromosomes of rainbow trout (Oncorhynchus mykiss) and to identify the sex chromosomes of coho salmon (O. kisutch), we used molecular markers OmyP9, 5S rDNA, and a growth hormone gene fragment (GH2), as FISH probes. Metaphase chromosomes were obtained from lymphocyte cultures from farm specimens of rainbow trout and coho salmon. Rainbow trout sex marker OmyP9 hybridizes on the sex chromosomes of rainbow trout, while in coho salmon, fluorescent signals were localized in the medial region of the long arm of one subtelocentric chromosome pair. This hybridization pattern together with the hybridization of a GH2 intron probe on a chromosome pair having the same morphology, suggests that a subtelocentric pair could be the sex chromosomes in this species. We confirm that in rainbow trout, one of the two loci for 5S rDNA genes is on the X chromosome. In males of this species that lack a heteromorphic sex pair (XX males), the 5S rDNA probe hybridized to both subtelocentrics. This finding is discussed in relation to the hypothesis of intraspecific polymorphism of sex chromosomes in rainbow trout.