Analysis of Foraging Behavior of Cattle Using a Wearable Camera under Diverse Vegetation

Although it is important to estimate the ingested plant species and the amount of forage intake by grazing animals, recording these items at the 1-bite scale has been difficult under diverse vegetation. Recent research confirmed that a small and inexpensive wearable camera is useful to determine ingested plant species and their proportion in total bites with high accuracy. In this study, we attempted to generate bite codes for cattle under diverse vegetation using wearable cameras. We used two cows which had a grazing experience in the previous year (GE) and the other two which had no grazing experience (NE). They grazed on a mountainous area (3 ha of sown pasture and 17 ha of forest) from late spring to mid-summer. A wearable camera (Panasonic HX-A500, 185 g) was fixed on the right cheek of the cows. Foraging behavior was continuously recorded for 120 min during morning foraging bouts, and direct observation was also conducted simultaneously. Bite codes were generated based on the morphological characteristics of ingested plants and the characteristics of foraging manner of the cows. Bite codes were classified into A (\u3e 100 cm), B (100–60 cm), and C (\u3c 60 cm) based on foraging height, then further classified into 5 types in A, 4 types in B, and 16 types in C (total 25 types) based on the differences in feeding manner. NE cows showed more frequent occurrence of the codes with low bite size than GE cows when foraging at a height of B in immediately after the start of grazing season. The results suggest that bite codes reflect bite size and thus can provide a precise understanding of their foraging behavior. It was also suggested that changes in bite codes due to the accumulation of grazing experience may affect foraging efficiency of grazing cattle

Comprehensive microarray-based analysis for stage-specific larval camouflage pattern-associated genes in the swallowtail butterfly, Papilio xuthus

<p>Abstract</p> <p>Background</p> <p>Body coloration is an ecologically important trait that is often involved in prey-predator interactions through mimicry and crypsis. Although this subject has attracted the interest of biologists and the general public, our scientific knowledge on the subject remains fragmentary. In the caterpillar of the swallowtail butterfly <it>Papilio xuthus</it>, spectacular changes in the color pattern are observed; the insect mimics bird droppings (mimetic pattern) as a young larva, and switches to a green camouflage coloration (cryptic pattern) in the final instar. Despite the wide variety and significance of larval color patterns, few studies have been conducted at a molecular level compared with the number of studies on adult butterfly wing patterns.</p> <p>Results</p> <p>To obtain a catalog of genes involved in larval mimetic and cryptic pattern formation, we constructed expressed sequence tag (EST) libraries of larval epidermis for <it>P. xuthus</it>, and <it>P. polytes </it>that contained 20,736 and 5,376 clones, respectively, representing one of the largest collections available in butterflies. A comparison with silkworm epidermal EST information revealed the high expression of putative blue and yellow pigment-binding proteins in <it>Papilio </it>species. We also designed a microarray from the EST dataset information, analyzed more than five stages each for six markings, and confirmed spatial expression patterns by whole-mount <it>in situ </it>hybridization. Hence, we succeeded in elucidating many novel marking-specific genes for mimetic and cryptic pattern formation, including pigment-binding protein genes, the melanin-associated gene <it>yellow-h3</it>, the ecdysteroid synthesis enzyme gene <it>3-dehydroecdysone 3b-reductase</it>, and <it>Papilio</it>-specific genes. We also found many cuticular protein genes with marking specificity that may be associated with the unique surface nanostructure of the markings. Furthermore, we identified two transcription factors, <it>spalt </it>and ecdysteroid signal-related <it>E75</it>, as genes expressed in larval eyespot markings. This finding suggests that <it>E75 </it>is a strong candidate mediator of the hormone-dependent coordination of larval pattern formation.</p> <p>Conclusions</p> <p>This study is one of the most comprehensive molecular analyses of complicated morphological features, and it will serve as a new resource for studying insect mimetic and cryptic pattern formation in general. The wide variety of marking-associated genes (both regulatory and structural genes) identified by our screening indicates that a similar strategy will be effective for understanding other complex traits.</p

Catalogue of epidermal genes: Genes expressed in the epidermis during larval molt of the silkworm Bombyx mori

<p>Abstract</p> <p>Background</p> <p>The insect cuticle is composed of various proteins and formed during the molt under hormonal regulation, although its precise composition and formation mechanism are largely unknown. The exhaustive catalogue of genes expressed in epidermis at the molt constitutes a massive amount of information from which to draw a complete picture of the molt and cuticle formation in insects. Therefore, we have catalogued a library of full-length cDNAs (designated epM) from epidermal cells during the last larval molt of <it>Bombyx mori</it>.</p> <p>Results</p> <p>Of the 10,368 sequences in the library, we isolated 6,653 usable expressed sequence tags (ESTs), which were categorized into 1,451 nonredundant gene clusters. Seventy-one clusters were considered to be isoforms or premature forms of other clusters. Therefore, we have identified 1,380 putative genes. Of the 6,653 expressed sequences, 48% were derived from 92 cuticular protein genes (RR-1, 24; RR-2, 17; glycine-rich, 29; other classes, 22). A comparison of epM with another epidermal EST data set, epV3 (feeding stage: fifth instar, day 3), showed marked differences in cuticular protein gene. Various types of cuticular proteins are expressed in epM but virtually only RR-1 proteins were expressed in epV3. Cuticular protein genes expressed specifically in epidermis, with several types of expression patterns during the molt, suggest different types of responses to the ecdysteroid pulse. Compared with other <it>Bombyx </it>EST libraries, 13 genes were preferentially included in epM data set. We isolated 290 genes for proteins other than cuticular proteins, whose amino acid sequences retain putative signal peptides, suggesting that they play some role in cuticle formation or in other molting events. Several gene groups were also included in this data set: hormone metabolism, P450, modifier of cuticular protein structure, small-ligand-binding protein, transcription factor, and pigmentation genes.</p> <p>Conclusion</p> <p>We have identified 1,380 genes in epM data set and 13 preferentially expressed genes in epidermis at the molt. The comparison of the epM and other EST libraries clarified the totally different gene expression patterns in epidermis between the molting and feeding stages and many novel tissue- and stage-specifically expressed epidermal genes. These data should further our understanding of cuticle formation and the insect molt.</p

Foraging Behavior of Cattle in a Diverse, Mountainous Grazing Land: Bite Size Estimation of Plants by Hand-plucking Method

Poster Session

Identification of the P-TEFb complex-interacting domain of Brd4 as an inhibitor of HIV-1 replication by functional cDNA library screening in MT-4 cells

AbstractWe conducted a phenotypic cDNA screening using a T cell line-based assay to identify human genes that render cells resistant to human immunodeficiency virus type 1 (HIV-1). We isolated potential HIV-1 resistance genes, including the carboxy terminal domain (CTD) of bromodomain-containing protein 4 (Brd4). Expression of GFP-Brd4-CTD was tolerated in MT-4 and Jurkat cells in which HIV-1 replication was markedly inhibited. We provide direct experimental data demonstrating that Brd4-CTD serves as a specific inhibitor of HIV-1 replication in T cells. Our method is a powerful tool for the identification of host factors that regulate HIV-1 replication in T cells

Substitution of the myristoylation signal of human immunodeficiency virus type 1 Pr55Gag with the phospholipase C-δ1 pleckstrin homology domain results in infectious pseudovirion production

The matrix domain (MA) of human immunodeficiency virus type 1 Pr55Gag is covalently modified with a myristoyl group that mediates efficient viral production. However, the role of myristoylation, particularly in the viral entry process, remains uninvestigated. This study replaced the myristoylation signal of MA with a well-studied phosphatidylinositol 4,5-biphosphate-binding plasma membrane (PM) targeting motif, the phospholipase C-δ1 pleckstrin homology (PH) domain. PH–Gag–Pol PM targeting and viral production efficiencies were improved compared with Gag–Pol, consistent with the estimated increases in Gag–PM affinity. Both virions were recovered in similar sucrose density-gradient fractions and had similar mature virion morphologies. Importantly, PH–Gag–Pol and Gag–Pol pseudovirions had almost identical infectivity, suggesting a dispensable role for myristoylation in the virus life cycle. PH–Gag–Pol might be useful in separating the myristoylation-dependent processes from the myristoylation-independent processes. This the first report demonstrating infectious pseudovirion production without myristoylated Pr55Gag

Repression of tyrosine hydroxylase is responsible for the sex-linked chocolate mutation of the silkworm, \u3cem\u3eBombyx mori\u3c/em\u3e

Pigmentation patterning has long interested biologists, integrating topics in ecology, development, genetics, and physiology. Wild-type neonatal larvae of the silkworm, Bombyx mori, are completely black. By contrast, the epidermis and head of larvae of the homozygous recessive sex-linked chocolate (sch) mutant are reddish brown. When incubated at 30 °C, mutants with the sch allele fail to hatch; moreover, homozygous mutants carrying the allele sch lethal (schl) do not hatch even at room temperature (25 °C). By positional cloning, we narrowed a region containing sch to 239,622 bp on chromosome 1 using 4,501 backcross (BC1) individuals. Based on expression analyses, the best sch candidate gene was shown to be tyrosine hydroxylase (BmTh). BmTh coding sequences were identical among sch, schl, and wild-type. However, in sch the ∼70-kb sequence was replaced with ∼4.6 kb of a Tc1-mariner type transposon located ∼6 kb upstream of BmTh, and in schl, a large fragment of an L1Bm retrotransposon was inserted just in front of the transcription start site of BmTh. In both cases, we observed a drastic reduction of BmTh expression. Use of RNAi with BmTh prevented pigmentation and hatching, and feeding of a tyrosine hydroxylase inhibitor also suppressed larval pigmentation in the wild-type strain, pnd+ and in a pS (black-striped) heterozygote. Feeding L-dopa to sch neonate larvae rescued the mutant phenotype from chocolate to black. Our results indicate the BmTh gene is responsible for the sch mutation, which plays an important role in melanin synthesis producing neonatal larval color

RNA interference in Lepidoptera: an overview of successful and unsuccessful studies and implications for experimental design

A

Large Scale Full-Length cDNA Sequencing Reveals a Unique Genomic Landscape in a Lepidopteran Model Insect, \u3cem\u3eBombyx mori\u3c/em\u3e

The establishment of a complete genomic sequence of silkworm, the model species of Lepidoptera, laid a foundation for its functional genomics. A more complete annotation of the genome will benefit functional and comparative studies and accelerate extensive industrial applications for this insect. To realize these goals, we embarked upon a large-scale full-length cDNA collection from 21 full-length cDNA libraries derived from 14 tissues of the domesticated silkworm and performed full sequencing by primer walking for 11,104 full-length cDNAs. The large average intron size was 1904 bp, resulting from a high accumulation of transposons. Using gene models predicted by GLEAN and published mRNAs, we identified 16,823 gene loci on the silkworm genome assembly. Orthology analysis of 153 species, including 11 insects, revealed that among three Lepidoptera including Monarch and Heliconius butterflies, the 403 largest silkworm-specific genes were composed mainly of protective immunity, hormone-related, and characteristic structural proteins. Analysis of testis-/ovary-specific genes revealed distinctive features of sexual dimorphism, including depletion of ovary-specific genes on the Z chromosome in contrast to an enrichment of testis-specific genes. More than 40% of genes expressed in specific tissues mapped in tissue-specific chromosomal clusters. The newly obtained FL-cDNA sequences enabled us to annotate the genome of this lepidopteran model insect more accurately, enhancing genomic and functional studies of Lepidoptera and comparative analyses with other insect orders, and yielding new insights into the evolution and organization of lepidopteran-specific genes

A Reversible Color Polyphenism in American Peppered Moth (Biston betularia cognataria) Caterpillars

Insect body color polyphenisms enhance survival by producing crypsis in diverse backgrounds. While color polyphenisms are often indirectly induced by temperature, rearing density, or diet, insects can benefit from immediate crypsis if they evolve polyphenisms directly induced by exposure to the background color, hence immediately deriving protection from predation. Here, we examine such a directly induced color polyphenism in caterpillars of the geometrid peppered moth (Biston betularia). This larval color polyphenism is unrelated to the genetic polymorphism for melanic phenotypes in adult moths. B. betularia caterpillars are generalist feeders and develop body colors that closely match the brown or green twigs of their host plant. We expand on previous studies examining the proximal cues that stimulate color development. Under controlled rearing conditions, we manipulated diets and background reflectance, using both natural and artificial twigs, and show that visual experience has a much stronger effect than does diet in promoting precise color matching. Their induced body color was not a simple response to reflectance or light intensity but instead specifically matched the wavelength of light to which they were exposed. We also show that the potential to change color is retained until the final (sixth) larval instar. Given their broad host range, this directly induced color polyphenism likely provides the caterpillars with strong protection from bird predation