http://hdl.handle.net/2123/5426 2013-05-22T03:33:55Z http://hdl.handle.net/2123/8990 Title: Cheaters sometimes prosper: targeted worker reproduction in honeybee (Apis mellifera) colonies during swarming Authors: Holmes, Michael J.; Oldroyd, Benjamin P.; Duncan, Michael; Allsopp, Michael H.; Beekman, Madeleine Abstract: Kin selection theory predicts that honeybee (Apis mellifera) workers should largely refrain from producing their own offspring, as the workers collectively have higher inclusive fitness if they rear the sons of their mother, the queen. Studies that have quantified levels of ovary activation and reproduction among workers have largely supported this prediction. In contrast we show here that the overall contribution of workers to male (drone) production is 4.2%, nearly 40 times higher than is generally reported, and is highest during reproductive swarming, when an average of 6.2% of the males genotyped are worker-produced. Similarly, workers in our samples were 100 times more likely to have active ovaries than previously assumed. Worker reproduction is seasonally influenced and peaks when colonies are rearing new queens. Not all worker subfamilies contribute equally to reproduction. Instead, certain subfamilies are massively over-represented in drone brood. By laying eggs within the period in which many colonies produce virgin queens, these rare worker subfamilies increase their direct fitness via their well-timed sons. 2013-01-01T00:00:00Z http://hdl.handle.net/2123/7028 Title: The Z stack of a vestibula larva of the sea urchin Heliocidaris erythrogramma recorded by confocal laser scanning microscopy Authors: Morris, Valerie B Abstract: The Z stack in this archive is representative of a vestibula larva of H. erythrogramma at an early stage in the development of the hydrocoele recorded in an Olympus FluoView 1000 laser scanning system. It is from a study of an echinoid with abbreviated larval development that shows the morphogenesis of the adult coeloms. The development is asymmetric with a larger left coelom forming on the larval-left side and a smaller right coelom forming on the larval-right side. The hydrocoele forms from the anterior part of the left coelom. The five lobes of the hydrocoele from which the pentamery of the adult derives take shape on the outer distal wall of the anterior part of the left coelom. The hydrocoele separates from the more posterior part of the left coelom, which becomes the left posterior coelom. Both larval and adult polarities are evident in this larva, supporting an origin from a single ancestral polarity. Description: The larva was fixed 36 hours after fertilization from a culture maintained at 20˚C. It was fixed in 2.5% (v/v) glutaraldehyde in filtered sea water for 1-2 hours, dehydrated in an ethanol series to 100% ethanol, then cleared in 2:1 (v/v) benzyl benzoate/benzyl alcohol. The larva, made autofluorescent by the glutaraldehyde fixation, was viewed in the clearant after mounting in a coverslip-sealed chamber. It was viewed in an Olympus FluoView 1000 laser scanning system (version 1.7.1.0) linked to an Olympus IX81 inverted microscope. The larva was excited at λex = 633 nm with a helium-neon laser and detected at λem = 645-745 nm. The Z stack was collected at a voxel dimension of 1.22 x 1.22 x 1.41 μm averaged over two frames in a 512 x 512 pixel array 12 bits/pixel using a 20x/NA 0.7 UplanApo objective lens. The orientation of the larva in the Z stack is such that view is of the larval-left side with larval posterior on the left in each image. To obtain a corrected orientation, as shown in the single tif image, the images should be rotated and also reflected, since the images in the Z stack were reflected by the IX81 inverted microscope. Each tif image can be viewed individually or the series of tif images contained in the folder can be analysed by image analysis software such as ImageJ available from the National Institutes of Health site (http://rsbweb.nih.gov/ij/). The larva is in frontal view with respect to the adult coeloms, providing an oral view of the hydrocoele and its five lobes. Associated publication Morris VB (2011) Coelomogenesis during the abbreviated development of the echinoid Heliocidaris erythrogramma and the developmental origin of the echinoderm pentameral body plan. (submitted for publication). 2010-11-23T00:00:00Z http://hdl.handle.net/2123/5438 Title: The Z stack of a late brachiolaria larva of the asterinid sea star Parvulastra exigua recorded by confocal laser scanning microscopy Authors: Morris, Valerie B Abstract: The Z stack in this archive is representative of a late brachiolaria larva of P. exigua recorded in the Olympus FluoView 1000 laser scanning system. It is from a study of the morphology of the coeloms and their interconnexions in a pre-metamorphic brachiolaria larva. The data of the Z stack show the coelom on the left and right sides of the larva linked anteriorly, over the head of the archenteron, by a common anterior coelom. The asymmetry of the larger left and the smaller right larval coeloms translates into the oral and aboral coeloms of the juvenile sea star. The morphology of the coeloms in a late brachiolaria larva of an asteroid has application in the search for morphological homology between the echinoderm classes and the deuterostome phyla. ***** Late brachiolaria larvae of P. exigua were fixed seven days after fertilization in 2.5% (v/v) glutaraldehyde in filtered sea water for 1-2 hours, dehydrated in an ethanol series to 100% ethanol, then cleared in 2:1 (v/v) benzyl benzoate/benzyl alcohol. The larvae, made autofluorescent by glutaraldehyde fixation, were mounted in the clearant in a chamber between glass coverslips that sealed a hole cut through a conventional microscope slide. The larvae were viewed in the Olympus FluoView 1000 laser scanning system (version 1.7.1.0) attached to an Olympus IX81 inverted microscope. Each larva was excited with a 633 nm helium-neon laser with the emission collected from 645-745 nm. A stack of images was collected along the Z axis (the Z stack) with a pixel dimension of 1.24 x 1.24 µm and a slice thickness of 1.10 µm averaged over two frames with a 20x UplanApo objective lens NA 0.7 in a 512 x 512 pixel array, 12 bits/pixel. Description: The Z stack is a series of images scanned in the XY plane at successive levels through the depth of the body of the larva. The orientation of the larva is such that view is of the larval ventral surface and larval anterior is on the left in each image. Since the images were reflected by the IX81 inverted microscope, the images should be reflected to obtain the correct left-right view. The images are tif images saved in sequence into one folder. Each tif image can be viewed individually or the series of tif images contained in the folder can be analysed by image analysis software such as ImageJ available from the National Institutes of Health site (http://rsbweb.nih.gov/ij/). Scale bar 100 µm. 2009-09-30T00:00:00Z