Ancient gene drives: an evolutionary paradox

This is the final version. Available on open access from the Royal Society via the DOI in this recordSelfish genetic elements such as selfish chromosomes increase their transmission rate relative to the rest of the genome and can generate substantial cost to the organisms that carry them. Such segregation distorters are predicted to either reach fixation potentially causing population extinction, or more commonly, promote the evolution of genetic suppression to restore transmission to equality. Many populations show rapid spread of segregation distorters, followed by the rapid evolution of suppression. However, not all drivers display such flux, instead persisting at stable frequencies in natural populations for decades, perhaps hundreds of thousands of years, with no sign of suppression evolving or the driver spreading to fixation. This represents a major evolutionary paradox. How can drivers be maintained long-term at stable frequencies? And why has suppression not evolved as is the case in many other gene drive systems? Here we explore potential factors that may explain the persistence of drive systems, focusing on the ancient sex-ratio SR driver in the fly Drosophila pseudoobscura. We discuss potential solutions to the evolutionary mystery of why suppression does not appear to have evolved in this system, and address how long-term stable frequencies of gene-drive can be maintained. Finally, we speculate whether ancient drivers may be functionally and evolutionarily distinct to young drive systems.Natural Environment Research Council (NERC

Penis evolution across species: divergence and diversity

This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordThe penis is an incredibly diverse and rapidly evolving structure, such that even in closely related species that otherwise differ very little in their morphology, penis form can be highly differentiated. Penises are also much more complex than their fundamental function — sperm transfer — would seem to require. The rapid divergent evolution of male structures is typically the signature of traits under sexual selection and the current evidence suggests the penis is no different in this regard. Despite the general agreement that sexual selection is the main driver of penis evolution, many questions about penis evolution remain unresolved. Furthermore, the penis might be an ideal characteristic on which to focus in the drive to link phenotype with genotype

Inbreeding alters intersexual fitness correlations in Drosophila simulans.

PublishedJournal ArticleIntralocus sexual conflict results from sexually antagonistic selection on traits shared by the sexes. This can displace males and females from their respective fitness optima, and negative intersexual correlations (r mf) for fitness are the unequivocal indicator of this evolutionary conflict. It has recently been suggested that intersexual fitness correlations can vary depending on the segregating genetic variation present in a population, and one way to alter genetic variation and test this idea is via inbreeding. Here, we test whether intersexual correlations for fitness vary with inbreeding in Drosophila simulans isolines reared under homogenous conditions. We measured male and female fitness at different times following the establishment of isofemale lines and found that the sign of the association between the two measures varied with time after initial inbreeding. Our results are consistent with suggestions that the type of genetic variation segregating within a population can determine the extent of intralocus sexual conflict and also support the idea that sexually antagonistic alleles segregate for longer in populations than alleles with sexually concordant effects.Foundation for Polish Science (FNP)NER

Ethnic disparity in 21-hydroxylase gene mutations identified in Pakistani congenital adrenal hyperplasia patients

Background: Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders caused by defects in the steroid 21 hydroxylase gene (CYP21A2). We studied the spectrum of mutations in CYP21A2 gene in a multi-ethnic population in Pakistan to explore the genetics of CAH. Methods: A cross sectional study was conducted for the identification of mutations CYP21A2 and their phenotypic associations in CAH using ARMS-PCR assay. Results: Overall, 29 patients were analyzed for nine different mutations. The group consisted of two major forms of CAH including 17 salt wasters and 12 simple virilizers. There were 14 phenotypic males and 15 females representing all the major ethnic groups of Pakistan. Parental consanguinity was reported in 65% cases and was equally distributed in the major ethnic groups. Among 58 chromosomes analyzed, mutations were identified in 45 (78.6%) chromosomes. The most frequent mutation was I2 splice (27%) followed by Ile173Asn (26%), Arg 357 Trp (19%), Gln319stop, 16% and Leu308InsT (12%), whereas Val282Leu was not observed in this study. Homozygosity was seen in 44% and heterozygosity in 34% cases. I2 splice mutation was found to be associated with SW in the homozygous. The Ile173Asn mutation was identified in both SW and SV forms. Moreover, Arg357Trp manifested SW in compound heterozygous state. Conclusion: Our study showed that CAH exists in our population with ethnic difference in the prevalence of mutations examined

Cultural Resources Investigations for the Oncor Permian Basin – Culberson 138 kV Transmission Line Project, Culberson, Reeves, and Ward Counties, Texas

URS Corporation (URS) was retained by Oncor Electric Delivery Company, LLC (Oncor) to conduct an intensive cultural resources survey of the new Permian Basin - Culberson 138 kilovolt (kV) Double-Circuit Transmission Line Project (Project) right-of-way (ROW) located in Culberson, Reeves, and Ward Counties, Texas. The proposed 70-foot (ft) (21-meter [m]) wide Project ROW encompasses approximately 825 acres and traverses a total of approximately 97 miles of rural lands between the existing Oncor Permian Basin Switching Station, located approximately four miles west of Monahans, Texas in Ward County, to the existing Oncor Culberson Switching Station, located approximately 17 miles south of the Texas/New Mexico state line in Culberson County. This includes 88.7 miles of the original route, along with 8.3 miles of additional segments that were evaluated. Currently, the Project is not subject to federal funding or permitting; therefore, no review under Section 106 of the National Historic Preservation Act of 1966, as amended, is required. Should the Project subsequently become subject to federal funding or permitting, the cultural resources investigations and site evaluations reported herein will be updated and coordinated with the Texas Historical Commission (THC) as part of fulfilling any Section 106 requirements that may arise at a later date. While the majority of the Project is located on private land, an approximately 6-mile long segment of the Project ROW traverses lands owned by University Lands (UL), which is a political subdivision of the State of Texas. Consequently, this portion of the project falls within the purview of the Antiquities Code of Texas, which requires the THC to review actions that have the potential to disturb prehistoric or historic sites in the public domain. In order to comply with the Antiquities Code, Antiquities Permit No. 7848 was obtained from the THC for the UL-owned lands, and the survey methods for this portion of the Project followed the THC’s archaeological survey standards for Texas. For the remaining areas of the Project, all cultural resources investigations were carried out in conformance with the methodologies outlined in the THC-approved Generic Research Design for Archaeological Surveys of Oncor Electric Delivery Electric Transmission Line Projects in Texas (PBS&J 2008). The cultural resources survey was conducted between December 7, 2015 and May 5, 2016, and consisted of an intensive 100 percent pedestrian survey and shovel testing within the Project ROW. The survey resulted in the identification of 16 newly-recorded sites and one previously recorded site (41WR85). Site forms were completed for each of the 16 newly identified archaeological sites, and trinomials were obtained from the Texas Archeological Research Laboratory. In addition, 16 isolated finds (IFs) were identified; however no site forms were prepared for IFs. All sites within the Project ROW were located in areas of eroded and/or mixed soils, lacked diagnostic artifacts, and were found to exhibit poor integrity context due to prior disturbances. Based on these observations, the portions of these sites within the Project ROW do not meet National Register of Historic Places (NRHP) and State Antiquities Landmark (SAL) eligibility requirements. However, because each of these sites appears to extend beyond the current Project ROW boundary, they have not been evaluated in their entirety and their overall NRHP and SAL eligibility is recommended to be Undetermined. Due to a lack of research potential and integrity, all IFs are recommended as not eligible for NRHP or SAL designation. During the survey, a small bedrock cavity was observed at site 41CU835. Due to safety concerns about the surrounding ground stability, this feature could not be fully investigated. The ground immediate adjacent to the cavity, as well as the upper two feet of the cavity, did not present any indications that it was culturally related, or that the cavity extended much deeper. The entirety of the observed cavity appeared to be too narrow to have served as an effective place of interment. However, based on survey level data, the cultural utilization of this feature could not be entirely ruled out. It was recommended that construction activities avoid this cavity and that site monitoring during construction be conducted, until such time as any cultural association is definitively ruled out, or until it can be confirmed that no construction impacts to the cavity would take place. A geomorphological assessment revealed that selected areas within the Project ROW potentially exhibit the necessary pedologic and geomorphic conditions for the deep burial and preservation of cultural deposits. These areas represent a combined total of 15.5 linear miles (25 kilometers) of Project ROW. In accordance with the Generic Research Design, monitoring was recommended for any transmission pole excavations in the areas that were assessed as exhibiting high geoarchaeological potential. An interim draft report of the foregoing recommendations was submitted to the THC on April 27, 2017. On May 26, 2017, the THC concurred with all interim report recommendations. During preparations for the monitoring effort, URS was notified by Oncor that a majority of the Project had already been constructed, including those areas recommended for monitoring. The only location that had not yet been constructed was the bedrock cavity at site 41CU835. On May 24, 2017, a meeting between Oncor, URS, and the THC resulted in an agreement that monitoring should be undertaken during construction activities near the bedrock cavity at site 41CU835. In addition, it was agreed that spot-checks would be performed within a subset of the previously constructed structures within high geoarchaeological probability areas, including portions of the Project owned by UL. Following completion of these tasks, it was agreed that a comprehensive revised draft report of investigations and findings (current report) would be submitted to the THC for review and project closure. Subsequent investigations at the bedrock cavity at 41CU835 were carried out from July 10-11, 2017. During the site visit, it was established that the cavity is located approximately 30 m to the southeast of the proposed location of monopole structure No. 56/3. Following additional inspections, it was possible to rule out any prehistoric use of this natural feature. The immediate area around the cavity was taped off for safety reasons so that other related construction activities would not adversely impact the cavity or surrounding area. On July 11, 2017, monitoring was carried out for the excavation of monopole structure no. 56/3. Soil stratigraphy was recorded for the total depth of the excavation, which was 20 ft. No cultural materials were identified From August 12-13, 2017, URS archaeologists performed spot-checks for 99 monopoles, including 53 structures within the Project ROW extending approximately 10 kilometers (km) west of the Pecos River in Reeves County; 22 structures within the Project ROW extending approximately 4 km east of the Pecos River in Ward County; and 24 structures within the Project ROW extending approximately 4.5 km across Monument Draw within UL in Ward County. Spot-checking included visual inspection and photo documentation of disturbances, as well as ground surface inspection to identify cultural resources. The Project ROW around each monopole exhibited construction related disturbances from equipment access roads and from drilling operations. No evidence was found that indicated any deeply buried cultural resource sites were impacted from auguring. Within the intervening areas between monopoles, however, a total of two previously unrecorded, low-density historic surface scatters (41RV128 and 41RV129) and three new IFs (H-07, H08, and P-28) were identified and recorded. Both sites were found to exhibit poor integrity due to prior disturbances, and low research potential due to minimal information potential. The portions of these sites within the Project ROW were not found to meet NRHP and SAL eligibility requirements. However, because each of these sites appears to extend beyond of the current Project ROW boundary, they have not been evaluated in their entirety and their overall NRHP and SAL eligibility is recommended to be Undetermined. The three new IFs are recommended as not eligible for NRHP or SAL designation. Based on the final results of the survey, monitoring, and spot-checking investigations, no cultural resources sites eligible for listing in the NRHP or that merit SAL designation within the Project ROW will be affected by the Project, and it is recommended that the project be allowed to proceed. Should the dimensions of the Project ROW change, additional archaeological investigations may be warranted. Should any unmarked prehistoric or historic human remains or burials be encountered at any point during the project, the area of the remains is considered a cemetery under current Texas law. All cemeteries are protected under State law and cannot be disturbed. Section 28.03(f) of the Texas Penal Code provides that intentional damage or destruction inflicted on a human burial site is a state jail felony. If a cemetery is identified in the Project ROW, all work in the immediate area of the discovery must cease and the THC must be notified by contacting the History Programs Division at (512) 463-5853 and the Archeology Division at (512) 463-6096. Following consultation with the THC, a treatment or avoidance plan would be developed and implemented. No artifacts were collected during the survey. Pursuant to 13 TAC 26.17, correspondence, field records, and photographs generated during field investigations have been prepared for permanent curation at the Texas Archeological Research Laboratory, Austin, Texas

The impact of female mating strategies on the success of insect control technologies

Attempts to control insect pests and disease vectors have a long history. Recently, new technology has opened a whole new range of possible methods to suppress or transform natural populations. But it has also become clear that a better understanding of the ecology of targeted populations is needed. One key parameter is mating behaviour. Often modified males are released which need to successfully reproduce with females while competing with wild males. Insect control techniques can be affected by target species’ mating ecology, and conversely mating ecology is likely to evolve in response to manipulation attempts. A better understanding of (female) mating behaviour will help anticipate and overcome potential challenges, and thus make desirable outcomes more likely

Sexual selection drives the evolution of male wing interference patterns.

This is the author accepted manuscriptThe seemingly transparent wings of many insects have recently been found to display unexpected structural coloration. These structural colours (wing interference patterns: WIPs) may be involved in species recognition and mate choice, yet little is known about the evolutionary processes that shape them. Furthermore, to date investigations of WIPs have not fully considered how they are actually perceived by the viewers' colour vision. Here, we use multispectral digital imaging and a model of Drosophila vision to compare WIPs of male and female Drosophila simulans from replicate populations forced to evolve with or without sexual selection for 68 generations. We show that WIPs modelled in Drosophila vision evolve in response to sexual selection and provide evidence that WIPs correlate with male sexual attractiveness. These findings add a new element to the otherwise well-described Drosophila courtship display and confirm that wing colours evolve through sexual selection.Natural Environment Research Council (NERC)Leverhulme Trus