Whole-Genome Sequences of SARS-CoV-2 Isolates from the Dominican Republic.

Here, we report the genome sequences of five severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains that were obtained from symptomatic individuals with travel histories during community surveillance in the Dominican Republic in 2020. These sequences provide a starting point for further genomic studies of gene flow and molecular diversity in the Caribbean nation. Phylogenetic analysis suggests that all genomes correspond to the B.1 variant.

GHEP-ISFG collaborative exercise on mixture profiles (GHEP-MIX06). Reporting conclusions: Results and evaluation.

One of the main goals of the Spanish and Portuguese-Speaking Group of the International Society for Forensic Genetics (GHEP-ISFG) is to promote and contribute to the development and dissemination of scientific knowledge in the field of forensic genetics. Due to this fact, GHEP-ISFG holds different working commissions that are set up to develop activities in scientific aspects of general interest. One of them, the Mixture Commission of GHEP-ISFG, has organized annually, since 2009, a collaborative exercise on analysis and interpretation of autosomal short tandem repeat (STR) mixture profiles. Until now, six exercises have been organized. At the present edition (GHEP-MIX06), with 25 participant laboratories, the exercise main aim was to assess mixture profiles results by issuing a report, from the proposal of a complex mock case. One of the conclusions obtained from this exercise is the increasing tendency of participating laboratories to validate DNA mixture profiles analysis following international recommendations. However, the results have shown some differences among them regarding the edition and also the interpretation of mixture profiles. Besides, although the last revision of ISO/IEC 17025:2017 gives indications of how results should be reported, not all laboratories strictly follow their recommendations. Regarding the statistical aspect, all those laboratories that have performed statistical evaluation of the data have employed the likelihood ratio (LR) as a parameter to evaluate the statistical compatibility. However, LR values obtained show a wide range of variation. This fact could not be attributed to the software employed, since the vast majority of laboratories that performed LR calculation employed the same software (LRmixStudio). Thus, the final allelic composition of the edited mixture profile and the parameters employed in the software could explain this data dispersion. This highlights the need, for each laboratory, to define through internal validations its criteria for editing and interpreting mixtures, and to continuous train in software handling.

The first synthesis of enantiopure alpha-amino ketimines and amino aziridines.

Chiral 1-aminoalkyl chloromethyl ketimines 2 are synthesized in enantiomerically pure form starting from 1-aminoalkyl chloromethyl ketones 1 and different amines. Reduction of amino ketimines 2 and subsequent spontaneous cyclization affords aminoalkyl aziridines 3 with high diastereoisomeric excess and without detectable racemization.

Forensic identification of skeletal remains from members of Ernesto Che Guevara's guerrillas in Bolivia based on DNA typing.

We report the positive identification of several members of the guerrillas led by Ernesto "Che" Guevara on the 1960 s in Bolivia by means of DNA fingerprinting. Successful DNA typing of both short tandem repeat loci and the hypervariable region of the human mitochondrial DNA was achieved after extracting total DNA from bones obtained from two burial sites. Given the size of the Cuban database for the STR allele frequencies, a conservative approach was followed to estimate the statistical significance of the genetic evidence. The estimated probabilities of paternity for the two cases in which the paternity logic was applied were higher than 99%. One case was analyzed using mitochondrial DNA and could not be excluded from the identity proposed by the forensic anthropology team. A fourth case was identified by exclusion, on the basis of the positive identification of the other remains, the historical and other anthropological evidence.

Differential constitutive expression of interferon genes in early mouse embryos.

Recent evidence suggests that several processes during mammalian embryogenesis may be regulated by IFNs or IFN-like molecules. With the use of MAPPing, the simultaneous presence of transcripts homologous to IFN-alpha, IFN-beta, IRF-1, and IRF-2 was examined in mouse embryos and in embryonal carcinoma (EC) P19 cells, which are equivalent to epiblast cells of the early postimplantation blastocysts. Transcripts for IFN-alpha, but not for IFN-beta, were detected as maternal transcripts in the ovulated oocyte and persisted over early embryogenesis. IRF-1 transcripts appeared only after the first cell cleavage in the two-cell stage embryo. IRF-2 transcripts were analyzed only in EC P19 cells and were found in both undifferentiated (D-) and differentiated (D+) cells. The IFN-alpha transcripts present in (D-) P19 cells were cloned and the partial cDNA sequences determined. Mu IFN-alpha A and a new Mu IFN-alpha species (Mu IFN-alpha 12) were isolated from (D-) P19 cells. The presence of constitutive IFN-alpha transcripts in early mouse embryos suggests a role for these molecules during embryogenesis.

The sound of the DNA language.

A new method is described for the study of DNA language employing the communicative strength of music. An algorithm was created to "translate" codons into musical notes. The analysis of the musical transcriptions of DNA sequences suggests the presence of some structural features of DNA language hidden in human and mouse interferon alpha 1 genes.

The sound of the DNA language

A new method is described for the study of DNA language employing the communicative strength of music. An algorithm was created to ®translate® codons into musical notes. The analysis of the musical transcriptions of DNA sequences suggests the presence of some structural features of DNA language hidden in human and mouse interferon alpha 1 genes

Use of F1 progeny of HolsteinxZebu cross cattle as oocyte donors for in vitro embryo production and gene microinjection.

This study was designed to determine the possibility of using F1 crossbreed cattle (HolsteinxZebu) as donors of oocytes for in vitro fertilization (IVF) and for pronuclear gene microinjection into in vitro-produced embryos. In the first part of the experiment oocytes from Bos taurus (Holstein), Bos indicus (Zebu) and F1 crossbred Bos taurusxBos indicus (HolsteinxZebu) genotypes were inseminated with Bos taurus (Holstein) semen and were allocated for in vitro embryo production using conventional IVF procedures. No differences were observed on the in vitro maturation (IVM) rates between breeds (HolsteinxHolstein:85%, ZebuxHolstein:84% and ZebuxHolsteinxHolstein:88%). Holstein cows yielded the highest number of cumulus oocyte complexes (6.8 per ovary) for in vitro maturation, differing (P<0.05) from ZebuxHolstein and ZebuxHolsteinxHolstein F1 by 5.1 and 5.8, respectively. However, the Holstein breed also yielded the lowest percentage of cleavage (45.1 vs 71.9% for ZebuxHolstein and 65.1% for ZebuxHolsteinxHolstein). Of the 3 genotypes, the hybrid F1 breed was the most efficient source of oocytes for the production of embryos capable of reaching morulae and blastocyst stages (76/250; P<0.001). In the second part of the study, 599 oocytes from the F1 breed were fertilized in vitro, 1 group of 150 oocytes was used for the determination of the optimal pronuclear visualization period. The highest number of oocytes with 2 pronuclei was observed between 24 to 28 h after IVF (27 to 42%). The remaining 399 oocytes were microinjected with a gene construct bearing the bacterial lacZ gene as the reporter for gene expression. Survival of embryos to microinjection was 73.8%, and 45.5% of them (50/110) cleaved in culture. Of the microinjected embryos, 1 out of 50 showed beta-galactosidase activity. These findings indicate that a tropical crossbreed of cattle (ZebuxHolsteinxHolstein) can be used as a source of oocytes for IVF programs and gene microinjection studies.

Production of transgenic mice and rabbits that carry and express the human tissue plasminogen activator cDNA under the control of a bovine alpha S1 casein promoter.

One-cell embryos from mice and rabbits were microinjected with a hybrid gene composed of 1.6 kilobases (kb) promoter/regulatory sequences of the bovine alphaS1 casein gene fused to the complementary DNA (cDNA) encoding for the human tissue plasminogen activator (htPA) and 3'untranslated sequences from rabbit beta-globin and SV 40 genes. Transgenic mice and rabbits that carry the htPA gene were obtained. In mice, 11 founder females were generated, and 6 of them expressed low levels (about 50 mug/ml) of htPA in their milk. Some of the transgenic mice showed rearrangements of the microinjected DNA sequences as judged by Southern blot analysis. A position-dependent expression of the transgene is suspected to occur. The only live-born founder transgenic rabbit obtained was a male, and it transmitted the transgene in a Mendelian fashion to F1 females, which expressed htPA at very low levels (8 to 50 ng/ml). Although the 1.6-kb bovine alphaS1 casein promoter that was used directs the synthesis of htPA specifically to the mammary gland, it may not be sufficient for a high level of expression.