The relationship between androgen receptor gene polymorphism, aggression and social status in young men and women

In both sexes, aggression has been described as a critical trait to acquire social status. Still, almost uniquely in men, the link between aggressiveness and the genetic background of testosterone sensitivity measured from the polymorphism in the androgen receptor (AR) gene has been previously investigated. We assessed the relevance of the AR gene to understand aggression and how aggressiveness affects social status in a cross-sectional study of 195 participants, for the first time in both young men and women. We estimated polymorphism sequences from saliva and measured aggression and self-perceived social status. Unfortunately, the results did not support our prediction because we did not find any of the expected relationships. Therefore, the results suggest that the genetic association between aggressive mechanisms and polymorphism of the AR gene is less straightforward than expected, at least in men, and seems to indicate that aggression is not usually used to gain social status in our populatio

Androgen receptor gene and sociosexuality. Does fighting ability moderate the effect of genetics in reproductive strategies?

Springer Nature remains neutral with regard to juris dictional claims in published maps and institutional affiliations.Sociosexuality is a reliable proxy to evaluate the trade-off between short-term and long-term human mating strategies. The androgen receptor (AR) gene CAG-repeats polymorphism regulates the effect of testosterone and the expression of testosterone-related traits commonly associated with short-term mating strategies. According to the strategic pluralism hypothesis, a more effective receptor would prompt a short-term mating strategy to maximize the number of sexual partners, but studies are inconclusive and contradictory. The effect of a particular gene in behavior is frequently small and affected by the social environment and other variables, particularly psychological and personality traits. In the current study we propose the effect of the AR gene polymorphism in sociosexuality to be moderated by self-perceived fighting ability, a psychological attribute relevant in intrasexual competition. Our objective is to reveal if the CAG polymorphism is associated with a short-term strategy as expected from the strategic pluralism hypothesis, or conversely with long-term investments to maximize parental care. We fail to find any effect of the CAG polymorphism over mating strategies. However, self-perceived fighting ability is related to short-term mating orientation but not to the number of past sexual partners. In conclusion, we find no clear evidence about the potential role of CAG polymorphism of the AR gene over sociosexual attitudes and behavior. However, results from other studies suggest that there is evidence that genetic factors influence sociosexuality, but it is necessary to consider simultaneously more than a single genetic polymorphism and other psychological and physiological variablesThis study was supported by a postdoctoral proj ect from Universidad del Desarrollo for author Nohelia T. Valenzuela and funded by the project BIOUAM03-2019 of the Departmento de Biología of the Universidad Autónoma de Madri

Dynamics of Rye Chromosome 1R Regions with High or Low Crossover Frequency in Homology Search and Synapsis Development

In many organisms, homologous pairing and synapsis depend on the meiotic recombination machinery that repairs double-strand DNA breaks (DSBs) produced at the onset of meiosis. The culmination of recombination via crossover gives rise to chiasmata, which locate distally in many plant species such as rye, Secale cereale. Although, synapsis initiates close to the chromosome ends, a direct effect of regions with high crossover frequency on partner identification and synapsis initiation has not been demonstrated. Here, we analyze the dynamics of distal and proximal regions of a rye chromosome introgressed into wheat to define their role on meiotic homology search and synapsis. We have used lines with a pair of two-armed chromosome 1R of rye, or a pair of telocentrics of its long arm (1RL), which were homozygous for the standard 1RL structure, homozygous for an inversion of 1RL that changes chiasma location from distal to proximal, or heterozygous for the inversion. Physical mapping of recombination produced in the ditelocentric heterozygote (1RL/1RLinv) showed that 70% of crossovers in the arm were confined to a terminal segment representing 10% of the 1RL length. The dynamics of the arms 1RL and 1RLinv during zygotene demonstrates that crossover-rich regions are more active in recognizing the homologous partner and developing synapsis than crossover-poor regions. When the crossover-rich regions are positioned in the vicinity of chromosome ends, their association is facilitated by telomere clustering; when they are positioned centrally in one of the two-armed chromosomes and distally in the homolog, their association is probably derived from chromosome elongation. On the other hand, chromosome movements that disassemble the bouquet may facilitate chromosome pairing correction by dissolution of improper chromosome associations. Taken together, these data support that repair of DSBs via crossover is essential in both the search of the homologous partner and consolidation of homologous synapsis

Frequency (%) of PMCs with asynapsis, partial synapsis or complete synapsis of the 1RL arm in the six types of plants studied.

<p>Among PMCs of the 1R/1R_inv heterozygote with complete synapsis, 45% showed non-homologous synapsis and 55% homologous synapsis. Mean number of PMCs = 119±16.</p

Matched regions in meiocytes with partial synapsis at mid zygotene (MZ), late zygotene (LZ) and pachytene (P) in homozygotes and heterozygotes for the inversion.

<p>p = proximal; d = distal; n = 1RL; i = 1RL_inv.</p>a<p>Synapsis covered only the centromere region in 74% of PMCs at MZ and 89% of PMCs at P.</p

Arrangement of telomeres (tel), rye centromeres (c), and rye heterochromatic chromomeres at early and mid prophase I stages in different rye chromosome combinations.

<p>Distal chromomeres of 1RS and 1RL are named S and L, respectively, Lsd designates the subdistal chromomere of the 1RL arm, and Lp the proximal chromomere of 1RL_inv. <b>A–B</b>) Cell at early leptotene (EL) with several telomere groups showing association of the centromeres and distal chromomeres of 1RL_inv, and separation of the proximal chromomeres. Centromere signals are larger than any telomere signals located in the opposite hemisphere. <b>C–D</b>) Cell at the leptotene-zygotene transition (LLEZ) showing a bipolar arrangement of the rye centromeres and the telomere cluster that denotes the bouquet formation. Both centromeres and heterochromatic chromomeres are separated. The S marker appears divided in two unequal subchromomeres (arrows) owing to chromosome elongation. <b>E–F</b>) Cell at mid zygotene (MZ) with the bouquet partially disorganized. Centromeres and distal chromomeres are associated. <b>G–H</b>) Cell at late zygotene (LZ) with bouquet dissolution. The 1RS subchromomeres (arrows) are joined because of chromatin condensation; all markers are associated. Bar represents 10 µm.</p

Synaptic configuration of the rye chromosome pair in cells at mid zygotene (MZ), late zygotene (LZ) and pachytene (P) in different lines.

<p><b>A, D, G, J</b>) DAPI image of each nucleus. <b>B, E, H, K</b>) Arrangement of telomeres labeled with probe pAt74 (green) and of the rye bivalent hybridized with probes, pUCM600, pAWRC.1, pSc74 (red) present in each nucleus. <b>C, F, I, L</b>) Schematic representation of the two rye homologues that synapse in each bivalent. <b>B, C</b>) 1RL and 1RL_inv show antiparallel arrangement and synapsis at both ends. <b>E, F</b>) Synapsis of the 1R_inv-1R_inv pair involves 1RS and the proximal region of 1RL_inv including the proximal chromomere. <b>H, I</b>) Chromosomes 1R and 1R_inv show complete homologous synapsis. <b>K, L</b>) Chromosomes 1R and 1R_inv underwent homologous synapsis of the short arm and non-homologous synapsis of the long arm. Bar represents 10 µm.</p

Position and frequency of crossovers that originated each type of bridge and fragment configuration observed at anaphase I in heterozygotes 1R/1R_inv and 1RL/1RL_inv.

<p>Position and frequency of crossovers that originated each type of bridge and fragment configuration observed at anaphase I in heterozygotes 1R/1R_inv and 1RL/1RL_inv.</p

Proximal and distal chiasma location between bi-armed or telocentric rye chromosomes and morphology of bivalents formed at metaphase I in different wheat-rye introgressed lines.

<p>Drawings show the position of chiasmata in each bivalent. <b>A–C</b>) The rye bivalent (arrow) was identified by FISH with the rye centromere DNA probe pAWRC.1 (strong red signals) and probe pSc74 (green). Telomeres (weak red signals) of all chromosomes were also labeled. Both wheat and rye chromosomes were stained with DAPI. <b>D–H</b>) Rye bivalents identified with rye specific DNA probes pUCM600 (red) pAWRC.1 (bright red) and pSc74 (green). Bars represent 10 µm.</p

The structure of the rye chromosome pair studied in a wheat background.

<p>Disomic introgressed wheat-rye lines for both chromosome 1R and the telocentric of its long arm (1RL) were homozygous for the standard structure (1R/1R and 1RL/1RL) homozygous for a pericentric inversion of its long (1R_inv/1R_inv and 1RL_inv/1RL_inv) or heterozygotes (1R/1R_inv and 1RL/1RL_inv). The approximated size of the inversion is indicated in homozygotes. Centromeres (red) and C-heterochromatin blocks S, Lp, Lsd and L (green) are rye-specific chromosome markers identified by FISH.</p