Starklorentsen6799
Evolving plasmids under different selection regimes in Escherichia coli, we find that antibiotics led to plasmid amplification, resulting in plasmid instability. Thus, under positive selection, suboptimal solutions for plasmid stability were maintained in the population hindering long-term plasmid persistence. Atezolizumab cost Indeed, a survey of Escherichia plasmids confirms that antibiotic resistance genes are rarely found on small plasmids. Our results show that a plasmid-mediated advantage for the host may manifest in reduced plasmid evolutionary success. Considering plasmids as autonomously evolving entities holds promise for understanding the factors that govern their evolution.Communication between male and female fruit flies during courtship is essential for successful mating, but, as with many other species, it is the female who decides whether to mate. Here, we show a novel role for ovipositor extrusion in promoting male copulation attempts in virgin and mated females and signaling acceptance in virgins. We first show that ovipositor extrusion is only displayed by sexually mature females, exclusively during courtship and in response to the male song. We identified a pair of descending neurons that controls ovipositor extrusion in mated females. Genetic silencing of the descending neurons shows that ovipositor extrusion stimulates the male to attempt copulation. A detailed behavioral analysis revealed that during courtship, the male repeatedly licks the female genitalia, independently of ovipositor extrusion, and that licking an extruded ovipositor prompts a copulation attempt. However, if the ovipositor is not subsequently retracted, copulation is prevented, as it happens with mated females. In this study, we reveal a dual function of the ovipositor while its extrusion is necessary for initiating copulation by the male, its retraction signals female acceptance. We thus uncover the significance of the communication between male and female that initiates the transition from courtship to copulation.Ancient DNA has significantly improved our understanding of the evolution and population history of extinct megafauna. However, few studies have used complete ancient genomes to examine species responses to climate change prior to extinction. The woolly rhinoceros (Coelodonta antiquitatis) was a cold-adapted megaherbivore widely distributed across northern Eurasia during the Late Pleistocene and became extinct approximately 14 thousand years before present (ka BP). While humans and climate change have been proposed as potential causes of extinction [1-3], knowledge is limited on how the woolly rhinoceros was impacted by human arrival and climatic fluctuations [2]. Here, we use one complete nuclear genome and 14 mitogenomes to investigate the demographic history of woolly rhinoceros leading up to its extinction. Unlike other northern megafauna, the effective population size of woolly rhinoceros likely increased at 29.7 ka BP and subsequently remained stable until close to the species' extinction. Analysis of the nuclear genome from a ∼18.5-ka-old specimen did not indicate any increased inbreeding or reduced genetic diversity, suggesting that the population size remained steady for more than 13 ka following the arrival of humans [4]. The population contraction leading to extinction of the woolly rhinoceros may have thus been sudden and mostly driven by rapid warming in the Bølling-Allerød interstadial. Furthermore, we identify woolly rhinoceros-specific adaptations to arctic climate, similar to those of the woolly mammoth. This study highlights how species respond differently to climatic fluctuations and further illustrates the potential of palaeogenomics to study the evolutionary history of extinct species.
To determine if the size and location of facial port-wine stains (PWS) can predict glaucoma risk in neonates.
Retrospective cohort study.
Children with facial PWS who had undergone ophthalmologic examination within 4weeks of their birth were included. Clinical information, including facial photographs, intraocular pressure, corneal diameter, optic disc cup-to-disc ratio, and Sturge-Weber syndrome (SWS) diagnoses were collected. Based on facial photographs, PWS distribution, eyelid involvement, and PWS scores according to degree of involvement in each embryonic facial vasculature distribution (segment [S]1, S2 and S3) were evaluated.
Among the 34 patients, 7 (21%) had bilateral PWS lesions. Eighteen (53%) had diagnoses of glaucoma. The proportion of eyes showing PWS involving both S1 and S2 was the highest (n= 15, 37%), and the frequency of glaucoma diagnosis (n= 9, 60%) was also the greatest. In eyelid involvement analysis, among the 7 eyes with only lower-eyelid lesions, 5 (83%) had glaucoma. Among the 11 eyes with only upper-eyelid lesions, however, 2 (18%) had diagnoses of glaucoma. A logistic regression model showed that the significant factors associated with glaucoma risk were greater PWS scores in S2 (odds ratio [OR] 3.604; 95% confidence interval 1.078-12.050; P= .037) or lower-eyelid involvement (OR 12.816; 95% CI 1.698-96.744; P= .013).
Among the newborns with facial PWS, 1) a greater extent of birthmarks involving the S2 area, and 2) lesions including the lower eyelid were associated with higher risk of glaucoma development within the neonatal period.
Among the newborns with facial PWS, 1) a greater extent of birthmarks involving the S2 area, and 2) lesions including the lower eyelid were associated with higher risk of glaucoma development within the neonatal period.
To identify characteristics of loci associated with locus-level sensitivity loss or improvement during treatment with N-acetylcysteine (NAC) in retinitis pigmentosa (RP).
Retrospective analysis of prospectively collected data in the FIGHT RP clinical trial.
Patients (n= 30) were treated with 600, 1,200, or 1,800mg of NAC twice daily for 3months and then 3 times/day for 3months. Microperimetry locus-level changes between baseline and month 6 were correlated with baseline characteristics of loci using regression models. The main outcome measurement was locus-level sensitivity change ≥6 dB.
Baseline mean sensitivity (3,468 loci; 51 evaluable eyes) was 7.7 dB and for foveal, parafoveal, and perifoveal loci were 20.2, 11.8, and 5.8 dB. During treatment, 287 loci (8.28%) increased ≥6 dB, and 119 of 1,613 loci with baseline sensitivity ≥6 dB decreased ≥6 dB (7.38%). A higher dose of NAC was associated with lower likelihood of sensitivity loss ≥6 dB (P= .033). Loci with low baseline sensitivity were more likely to decrease ≥6 dB (P= .