Most phaeophytes （brown algae） and rhodophytes （red algae） dwell exclusively in marine habitats and play important roles in marine ecology and biodiversity. Many of these brown and red algae are also important res...Most phaeophytes （brown algae） and rhodophytes （red algae） dwell exclusively in marine habitats and play important roles in marine ecology and biodiversity. Many of these brown and red algae are also important resources for industries such as food, medicine and materials due to their unique metabolisms and me-tabolites. However, many fundamental questions surrounding their origins, early diversification, taxonomy, and special metabolisms remain unsolved because of poor molecular bases in brown and red algal study. As part of the 1 000 Plant Project, the marine macroalgal transcriptomes of 19 Phaeophyceae species and 21 Rhodophyta species from China＇s coast were sequenced, covering a total of 2 phyla, 3 classes, 11 orders, and 19 families. An average of 2 Gb per sample and a total 87.3 Gb of RNA-seq raw data were generated. Approxi-mately 15 000 to 25 000 unigenes for each brown algal sample and 5 000 to 10 000 unigenes for each red algal sample were annotated and analyzed. The annotation results showed obvious differences in gene expres-sion and genome characteristics between red algae and brown algae;these differences could even be seen between multicellular and unicellular red algae. The results elucidate some fundamental questions about the phylogenetic taxonomy within phaeophytes and rhodophytes, and also reveal many novel metabolic pathways. These pathways include algal CO2 fixation and particular carbohydrate metabolisms, and related gene/gene family characteristics and evolution in brown and red algae. These findings build on known algal genetic information and significantly improve our understanding of algal biology, biodiversity, evolution, and potential utilization of these marine algae.展开更多
The color of compound eyes is an important biological characteristic of insects. A red eye color mutation is commonly found in the brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), a...The color of compound eyes is an important biological characteristic of insects. A red eye color mutation is commonly found in the brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), a serious insect pest of rice in tropical and temperate Asia. The genetic inheritance and physiological effect of the eye color mutation in the BPH have been studied, but the location of a red gene controlling the red eye mutant phenotype on a chromosome has not been elucidated. In this study, simple sequence repeats (SSRs), together with bulked segregant analysis (BSA), was performed to identify and map the location of the red gene. A total of 387 SSR markers distributed throughout the BPH autosome were used to survey two bulked DNA samples. Samples were generated from 29 brown-eyed and 29 red-eyed individuals derived from an F2 generation of a cross between brown-eyed wild type and red-eyed mutant colonies. The SSR marker BM20 was shown to be associated with the red eye mutant phenotype. Ninety-five offspring of the F2 generation were then used to map the gene. The present study constitutes the discovery of the location of the red gene, which may lead to the acquisition of the genetic determinant of the compound eye color mutation in BPH.展开更多
Fifty four, seven month old lambs, that had grazed perennial or annual pasture, were slaughtered and at 24 h post mortem m. longissimus lumborum samples were collected. Half of the fresh muscle section was sliced into...Fifty four, seven month old lambs, that had grazed perennial or annual pasture, were slaughtered and at 24 h post mortem m. longissimus lumborum samples were collected. Half of the fresh muscle section was sliced into three pieces and overwrapped with 15 micron polyvinyl chloride film and displayed under light (Lux = 1500) at 3℃ - 4℃. The remainder of the muscle section was vacuum packaged and aged for 4 weeks at 3℃, before slicing and display. Surface brownness and redness were measured over 3 days of simulated retail display. Aging in vacuum packs led to substantially less brownness and greater redness compared with fresh meat, over the entire three days of display. It was concluded that aging in vacuum packs could be a useful strategy for improving consumer acceptability of retail lamb in local markets, even where there is no logistical or transport need to extend the life of the meat.展开更多
Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not...Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania.Although hosts of Old World cuckoos(Cuculidae)often show geographic variation in egg rejection behavior,cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs.Thus,geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism.In this study,we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population,which may provide insight into low parasitism levels across eastern North America.Methods:We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism.Nests were tested across three nest stages and compared to control nests with no manipulations.Because rejection differed significantly by stage,we compared responses separately for each nest stage.We also monitored other songbird nests to identify parasitism frequencies on all potential hosts.Results:Red-wings showed significantly more rejections during the building stage,but not for the laying and incubation stages.Rejections during nest building involved mostly egg burials,which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg.Excluding these responses,red-wings rejected 15%of cowbird eggs,which is similar to rejection levels from other studies and populations.The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%.Conclusions:Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population.Alternatively,we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism.Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.展开更多
基金The National Natural Science Foundation of China under contract Nos 31140070,31271397 and 41206116the algal transcrip-tome sequencing was supported by 1KP Project(www.onekp.com)
文摘Most phaeophytes （brown algae） and rhodophytes （red algae） dwell exclusively in marine habitats and play important roles in marine ecology and biodiversity. Many of these brown and red algae are also important resources for industries such as food, medicine and materials due to their unique metabolisms and me-tabolites. However, many fundamental questions surrounding their origins, early diversification, taxonomy, and special metabolisms remain unsolved because of poor molecular bases in brown and red algal study. As part of the 1 000 Plant Project, the marine macroalgal transcriptomes of 19 Phaeophyceae species and 21 Rhodophyta species from China＇s coast were sequenced, covering a total of 2 phyla, 3 classes, 11 orders, and 19 families. An average of 2 Gb per sample and a total 87.3 Gb of RNA-seq raw data were generated. Approxi-mately 15 000 to 25 000 unigenes for each brown algal sample and 5 000 to 10 000 unigenes for each red algal sample were annotated and analyzed. The annotation results showed obvious differences in gene expres-sion and genome characteristics between red algae and brown algae;these differences could even be seen between multicellular and unicellular red algae. The results elucidate some fundamental questions about the phylogenetic taxonomy within phaeophytes and rhodophytes, and also reveal many novel metabolic pathways. These pathways include algal CO2 fixation and particular carbohydrate metabolisms, and related gene/gene family characteristics and evolution in brown and red algae. These findings build on known algal genetic information and significantly improve our understanding of algal biology, biodiversity, evolution, and potential utilization of these marine algae.
文摘The color of compound eyes is an important biological characteristic of insects. A red eye color mutation is commonly found in the brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), a serious insect pest of rice in tropical and temperate Asia. The genetic inheritance and physiological effect of the eye color mutation in the BPH have been studied, but the location of a red gene controlling the red eye mutant phenotype on a chromosome has not been elucidated. In this study, simple sequence repeats (SSRs), together with bulked segregant analysis (BSA), was performed to identify and map the location of the red gene. A total of 387 SSR markers distributed throughout the BPH autosome were used to survey two bulked DNA samples. Samples were generated from 29 brown-eyed and 29 red-eyed individuals derived from an F2 generation of a cross between brown-eyed wild type and red-eyed mutant colonies. The SSR marker BM20 was shown to be associated with the red eye mutant phenotype. Ninety-five offspring of the F2 generation were then used to map the gene. The present study constitutes the discovery of the location of the red gene, which may lead to the acquisition of the genetic determinant of the compound eye color mutation in BPH.
文摘Fifty four, seven month old lambs, that had grazed perennial or annual pasture, were slaughtered and at 24 h post mortem m. longissimus lumborum samples were collected. Half of the fresh muscle section was sliced into three pieces and overwrapped with 15 micron polyvinyl chloride film and displayed under light (Lux = 1500) at 3℃ - 4℃. The remainder of the muscle section was vacuum packaged and aged for 4 weeks at 3℃, before slicing and display. Surface brownness and redness were measured over 3 days of simulated retail display. Aging in vacuum packs led to substantially less brownness and greater redness compared with fresh meat, over the entire three days of display. It was concluded that aging in vacuum packs could be a useful strategy for improving consumer acceptability of retail lamb in local markets, even where there is no logistical or transport need to extend the life of the meat.
基金provided by a BEARS Grant and a Neag Undergraduate Research Grant from Kutztown University
文摘Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania.Although hosts of Old World cuckoos(Cuculidae)often show geographic variation in egg rejection behavior,cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs.Thus,geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism.In this study,we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population,which may provide insight into low parasitism levels across eastern North America.Methods:We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism.Nests were tested across three nest stages and compared to control nests with no manipulations.Because rejection differed significantly by stage,we compared responses separately for each nest stage.We also monitored other songbird nests to identify parasitism frequencies on all potential hosts.Results:Red-wings showed significantly more rejections during the building stage,but not for the laying and incubation stages.Rejections during nest building involved mostly egg burials,which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg.Excluding these responses,red-wings rejected 15%of cowbird eggs,which is similar to rejection levels from other studies and populations.The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%.Conclusions:Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population.Alternatively,we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism.Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.
