The reference genome and transcriptome of the limestone langur, Trachypithecus leucocephalus, reveal expansion of genes related to alkali tolerance.

BACKGROUND: Trachypithecus leucocephalus, the white-headed langur, is a critically endangered primate that is endemic to the karst mountains in the southern Guangxi province of China. Studying the genomic and transcriptomic mechanisms underlying its local adaptation could help explain its persistence within a highly specialized ecological niche. RESULTS: In this study, we used PacBio sequencing and optical assembly and Hi-C analysis to create a high-quality de novo assembly of the T. leucocephalus genome. Annotation and functional enrichment revealed many genes involved in metabolism, transport, and homeostasis, and almost all of the positively selected genes were related to mineral ion binding. The transcriptomes of 12 tissues from three T. leucocephalus individuals showed that the great majority of genes involved in mineral absorption and calcium signaling were expressed, and their gene families were significantly expanded. For example, FTH1 primarily functions in iron storage and had 20 expanded copies. CONCLUSIONS: These results increase our understanding of the evolution of alkali tolerance and other traits necessary for the persistence of T. leucocephalus within an ecologically unique limestone karst environment.

Frozen blastocyst transfer reduces incidence of ectopic pregnancy compared with fresh blastocyst transfer: a meta-analysis.

BACKGROUND: Ectopic pregnancy (EP) is the main cause of maternal death during early pregnancy. Blastocyst transfer (BT) reduces EP rates compared with cleavage stage embryo transfer (ET), and frozen ET reduces EP rates compared with fresh ET. However, data comparing the EP rate of fresh BT and frozen BT are limited. The objective of this meta-analysis was to determine whether frozen BT decreases the EP rate compared with fresh BT. MATERIALS AND METHODS: PUBMED, EMBASE, and Cochrane Library databases were searched for papers with no limitation on language and publication year. A systemic literature search identified 14 studies which met the inclusion criteria for further analysis. EP rate is our only outcome measure. All statistical analyses were carried out using RevMan software [version 5.3]. Random effects models were chosen to calculate the odds ratio (OR). RESULTS: Fourteen retrospective studies (n = 251,762 cycles) were finally analyzed, including 154,214 and 97,548 cycles undergoing fresh and frozen BT, respectively. Compared with fresh BT, the frozen BT was associated with an decrease in EP rate [OR = 1.79; 95% confidence interval (CI) = 1.37-2.34, heterogeneity was 71%], the EP rate was 1.74% (2683/154,214 pregnancies) for fresh BT and 0.97% (949/97,548 pregnancies) for frozen BT. The number of embryos transferred in subgroup analysis found that the incidence of EP in frozen BT is lower than fresh BT (OR = 1.62; 95% CI = 1.38-1.91), the EP rate was 1.2% (206/16,610 pregnancies) for one fresh BT and 0.8% (153/19,569 pregnancies) for one frozen BT, also the EP rate was 1.9% (78/4043 pregnancies) for two fresh BT and 1.1% (19/1790 pregnancies) for two frozen BT. CONCLUSIONS: Our meta-analysis found that frozen BT was associated with an decrease in EP rate compared with fresh BT in IVF/ICSI patients. We also found that a single frozen BT is the better choice as a method to reduce the incidence of EP.

[Results of requesting a second consecutive sperm ejaculate on the day of oocyte pick-up in assisted reproductive technology].

OBJECTIVE: To evaluate the results of requesting a second consecutive sperm ejaculate in order to reduce ICSI cycles by PESA or TESE on the day of oocyte pick-up in assisted reproductive technology (ART). METHODS: We collected 68 semen samples as a second consecutive ejaculate from 34 men, compared the semen volume and sperm concentration, motility and total count between the first and the second ejaculation, and analyzed the laboratory results and clinical outcomes of fertilization with the mixed sperm. RESULTS: The 34 males ejaculated twice within 4 hours by masturbation, with an interval of 26-183 (94.9 +/- 39.8) minutes between the first and second ejaculation. The volume of the first ejaculate was (2.0 +/- 1.4) ml, significantly higher than that of the second ([1.5 +/- 0.9] ml) (P = 0.007), although the numbers of motile sperm and grade a + b sperm of the first ([40.8 +/- 25.3]% and [30.9 +/- 22.4]%) were significantly lower than those of the second ([52.2 +/- 21.1]% and [39.9 +/- 17.5]%) (P < 0.05). There were no statistically significant differences in the sperm concentration or total sperm count between the two ejaculates (P > 0.05). The ICSI, IVF + ICSI, and IVF cycles were 3, 3 and 28 respectively among the 34 couples undergoing ART. The number of retrieved oocytes, normal fertilization rate, high quality embryo rate and frozen cycles/fresh transfer cycles ratio were 15.5 +/- 8.7, 57.0% (247/433), 58.7% (145/247) and 20/24 for the IVF cycle, 21.7 +/- 8.3, 61.5% (40/65), 67.5% (27/40) and 3/2 for the ICSI cycle, and 10.0 +/- 2.6, 72.4% (21/29), 66.7% (14/21) and 3/3 for the IVF + ICSI cycle. Fourteen live births were achieved out of the 18 pregnancies, including 6 healthy boys and 9 healthy girls. CONCLUSION: A clinical pregnancy rate of >30% can be achieved by requesting a second consecutive sperm ejaculate on the day of oocyte pick-up in order to collect more sperm and/or increase the total number of motile sperm for ART. And this method can avoid other invasive sperm processing techniques and the need of unnecessary micromanipulative fertilization.

Investigation of photoinduced electron transfer in model system of vitamin E-duroquinone by time-dependent density functional theory.

Photoinduced electron transfer of the model system composed of vitamin E and duroquinone has been investigated using time-dependent density functional theory. Calculations for the excited states tell that the photoexcitation of the model system can directly yield the charge transfer states in which the vitamin E moiety is positively charged but the duroquinone moiety is negatively charged. Our theoretical investigations indicate that the second charge transfer state of the model system can also be produced through the decay of higher locally excited state S(4). Since S(4) state in the model system corresponds to S(1) state of the isolated duroquinone used as a model for peroxyl radical, and S(2) state has the character of electron transfer from the tertiary amine group of the vitamin E moiety to the duroquinone moiety, the decay from S(4) to S(2) corresponds to the dynamic process following the photoexcitation of the duroquinone moiety of the model system, i.e., the initial stage of antioxidant reaction of vitamin E. Calculations of the kinetic parameters for the electron transfer have been carried out in the framework of the Marcus-Jortner-Levich formalism. Our calculations confirm that the electron transfer from S(4) to S(2) possesses the character of the inverted regime and the barrier is negligibly small.