Do allopatric male Calopteryx virgo damselflies learn species recognition?

Peer reviewe

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Do allopatric male Calopteryx virgo damselflies learn species recognition?

There is a growing amount of empirical evidence that premating reproductive isolation of two closely related species can be reinforced by natural selection arising from avoidance of maladaptive hybridization. However, as an alternative for this popular reinforcement theory, it has been suggested that learning to prefer conspecifics or to discriminate heterospecifics could cause a similar pattern of reinforced premating isolation, but this possibility is much less studied. Here, we report results of a field experiment in which we examined (i) whether allopatric Calopteryx virgo damselfly males that have not encountered heterospecific females of the congener C. splendens initially show discrimination, and (ii) whether C. virgo males learn to discriminate heterospecifics or learn to associate with conspecifics during repeated experimental presentation of females. Our experiment revealed that there was a statistically nonsignificant tendency for C. virgo males to show initial discrimination against heterospecific females but because we did not use sexually naïve individuals in our experiment, we were not able to separate the effect of innate or associative learning. More importantly, however, our study revealed that species discrimination might be further strengthened by learning, especially so that C. virgo males increase their association with conspecific females during repeated presentation trials. The role of learning to discriminate C. splendens females was less clear. We conclude that learning might play a role in species recognition also when individuals are not naïve but have already encountered potential conspecific mates.peerReviewe

Data from: Assessment of dysmyelination with RAFFn MRI: application to murine MPS I

Type I mucopolysaccharidosis (MPS I) is an autosomal recessive lysosomal storage disorder with neurological features. Humans and laboratory animals with MPS I exhibit various white matter abnormalities involving the corpus callosum and other regions. In this study, we first validated a novel MRI technique, entitled Relaxation Along a Fictitious Field in the rotating frame of rank n (RAFFn), as a measure of myelination and dysmyelination in mice. We then examined differences between MPS I mice and heterozygotes using RAFF5 and histology. RAFF5 (i.e., RAFFn with n = 5) relaxation time constants were highly correlated with histological myelin density (R2 = 0.68, P<0.001), and RAFF5 clearly distinguished between the hypomyelinated and dysmyelinated shiverer mouse and the wild-type mouse. Bloch-McConnell theoretical analysis revealed slower exchange correlation times and smaller exchange-induced relaxation rate constants for RAFF4 and RAFF5 compared to RAFF1-3, T1ρ, and T2ρ. These data suggest that RAFF5 may assess methylene protons in myelin lipids and proteins, though other mechanisms (e.g. detection of myelin-bound water) may also explain the sensitivity of RAFF5 to myelin. In MPS I mice, mean RAFF5 relaxation time constants were significantly larger for the striatum (P = 0.004) and internal capsule (P = 0.039), and marginally larger for the fornix (P = 0.15). Histological assessment revealed no differences between MPS I mice and heterozygotes in myelin density or corpus callosum thickness. Taken together, these findings support subtle dysmyelination in the brains of mice with MPS I. Dysmyelination may result from myelin lipid abnormalities caused by the absence of α-L-iduronidase. Our findings may help to explain locomotor and cognitive deficits seen in mice with MPS I

Assessment of dysmyelination with RAFFn MRI: application to murine MPS I.

Type I mucopolysaccharidosis (MPS I) is an autosomal recessive lysosomal storage disorder with neurological features. Humans and laboratory animals with MPS I exhibit various white matter abnormalities involving the corpus callosum and other regions. In this study, we first validated a novel MRI technique, entitled Relaxation Along a Fictitious Field in the rotating frame of rank n (RAFFn), as a measure of myelination and dysmyelination in mice. We then examined differences between MPS I mice and heterozygotes using RAFF5 and histology. RAFF5 (i.e., RAFFn with n = 5) relaxation time constants were highly correlated with histological myelin density (R2 = 0.68, P<0.001), and RAFF5 clearly distinguished between the hypomyelinated and dysmyelinated shiverer mouse and the wild-type mouse. Bloch-McConnell theoretical analysis revealed slower exchange correlation times and smaller exchange-induced relaxation rate constants for RAFF4 and RAFF5 compared to RAFF1-3, T1ρ, and T2ρ. These data suggest that RAFF5 may assess methylene protons in myelin lipids and proteins, though other mechanisms (e.g. detection of myelin-bound water) may also explain the sensitivity of RAFF5 to myelin. In MPS I mice, mean RAFF5 relaxation time constants were significantly larger for the striatum (P = 0.004) and internal capsule (P = 0.039), and marginally larger for the fornix (P = 0.15). Histological assessment revealed no differences between MPS I mice and heterozygotes in myelin density or corpus callosum thickness. Taken together, these findings support subtle dysmyelination in the brains of mice with MPS I. Dysmyelination may result from myelin lipid abnormalities caused by the absence of α-L-iduronidase. Our findings may help to explain locomotor and cognitive deficits seen in mice with MPS I

MRI relaxation time constant maps

Zipped folder containing MRI relaxation time constant maps. Files are meant to be opened and analyzed using the Aedes toolbox for MATLAB. See the publication in PLOS ONE for more details. Files are titled "MRI_[mouse identifier]_[MRI sequence].t1r [or .t1]". Mice 13021, 13224, 13255, N3, N4, and N5 are mice with MPS I; mice 13257, 13258, N1, N2, and N6 are heterozygotes

MRI analysis_for Dryad

Excel spreadsheet containing analyzed MRI data. The “MRI ROI comparison” tab contains mean relaxation time constants for each ROI in each animal for each sequence, as well as means for each genotype. The “MRI vs histology” tab contains correlation of tissue section-derived normalized optical density with MRI relaxation time constants for each MRI sequence. The “Outliers” tab contains analysis of each animal for outlying values (see the publication in PLOS ONE for details). Mice 13021, 13224, 13255, N3, N4, and N5 are mice with MPS I; mice 13257, 13258, N1, N2, and N6 are heterozygotes

Histology analysis_for Dryad

Excel spreadsheet containing analyzed histological data. The “Optical density” tab contains raw optical density values for each tissue section, normalized values, normalized means for each animal, and normalized means for each genotype. The “Outliers” tab contains analysis of each animal for outlying values (see the publication in PLOS ONE for details). The “cc thickness” tab contains raw data for corpus callosum thickness, comparison with atlas values for each section, animal means, and genotype means. Mice 13021, 13224, 13255, N3, N4, and N5 are mice with MPS I; mice 13257, 13258, N1, N2, and N6 are heterozygotes

Histology images

Zipped folder containing photomicrographs of mouse brain sections. Sections are from MPS I mice and IDUA heterozygotes, and are stained with the black gold stain. Images have been resized and converted to grayscale. Images are scaled to 173 pixels per millimeter unless noted otherwise in the filename (“..._NotToScale”). Files are titled "histology_[mouse identifier]_[tissue section identifier].tif". Mice 13021, 13224, 13255, N3, N4, and N5 are mice with MPS I; mice 13257, 13258, N1, N2, and N6 are heterozygotes