ライフサイエンスコーパス: Drosophila

1 SL, called Suppressor of Hairless [Su(H)] in Drosophila.

2 to perform conditional gene inactivation in Drosophila.

3 aspects of the developing sensory systems in Drosophila.

4 , interact at genetic and neuronal levels in Drosophila.

5 asurement of sleep and feeding in individual Drosophila.

6 equired for induction of the L2 wing vein in Drosophila.

7 xual size dimorphism (SSD) is established in Drosophila.

8 to function in transcription of RP genes in Drosophila.

9 yndrome that affects germline development in Drosophila.

10 gy and influences survival and locomotion in Drosophila.

11 ess is nearly identical to the same ratio in Drosophila.

12 ing has yet to be performed in vivo in adult Drosophila.

13 g neurons to innervate all target tissues in Drosophila.

14 ter release at the neuromuscular junction in Drosophila.

15 en linked to wasps' successful parasitism of Drosophila [6], but the composition of VLPs and their bi

16 Both levels operate in Drosophila [8, 12, 13].

17 similar behaviors in yeast, in vitro, and in Drosophila, a few showed anomalous behavior.

18 h for an interaction between neprilysins and Drosophila Abeta (dAbeta), a cleavage product of APPL.

19 report the visceral role of misato (mst) in Drosophila and its implications for the pathogenesis of

20 In Drosophila and mammalian macrophages, lysosomal dysfunct

21 ion of neuronal genetic control available in Drosophila and may be extended to other organisms where

22 Work on genetic model systems such as Drosophila and mouse has shown that the fundamental mech

23 Analysis of chimeric Drosophila and mouse TRPA1 channels reveal a critical ro

24 for high-throughput analysis of behavior in Drosophila and other animals.

25 A regulation on a complex innate behavior in Drosophila and suggests that miRNAs may be core componen

26 dherin-associated beta-catenin (Armadillo in Drosophila) and p120-catenin to induce rhomboid.

27 by ancient CELF family homologs in chicken, Drosophila, and Caenorhabditis elegans suggests this ant

28 ein, significantly affects behavior in mice, Drosophila, and Caenorhabditis elegans Yet, the mechanis

29 ia as an ecologically important taste cue in Drosophila, and shows that it can activate circuits that

30 our understanding of humidity sensing in the Drosophila antenna, uncover a neuronal substrate for ear

31 nscriptional reporters that are dependent on Drosophila AP-1 (dAP-1) and STAT92E.

32 Using Drosophila as a model, we here show that a specific popu

33 le stem cells are present in adult muscle of Drosophila as small, unfused cells observed at the surfa

34 increase in labeling speed in both mice and Drosophila, at the expense of a considerable drop in abs

35 ila SCA5 model in which an equivalent mutant Drosophila beta-spectrin is expressed in neurons that ex

36 human cells, mouse embryonic stem cells, and Drosophila Biochemical analysis of BRWD2 demonstrated an

37 field abundance of the rainforest fruit fly Drosophila birchii to ecological change across gradients

38 essing sites in Glass bottom boat (Gbb), the Drosophila BMP7 ortholog, can produce distinct ligand fo

39 ssing, we investigated two cell types in the Drosophila brain (A2 and B1 cells) that are postsynaptic

40 Temperature-sensing neurons in the Drosophila brain cooperate with the central circadian cl

41 s, developmental and structural units of the Drosophila brain that provide a framework of connections

42 ar neurotoxic Abeta peptides in the AD model Drosophila brain through a Draper/STAT92E/JNK cascade th

43 In the Drosophila brain, LRP4 localizes to the nerve terminals

44 is an emerging model organism separated from Drosophila by 350 million years of evolution that disp

45 he genetic variance in susceptibility to the Drosophila C virus (DCV) in populations of Drosophila me

46 Drosophila CaMKII-null mutants remain viable throughout

47 An 'interactome' screen of all Drosophila cell-surface and secreted proteins containing

48 t Torso expressed at high levels in cultured Drosophila cells is activated by individual application

49 Here we report that Drosophila centrosomin (cnn) expresses two major protein

50 The Drosophila circadian clock is extremely sensitive to lig

51 ptional regulation and the role of miRNAs in Drosophila circadian rhythms.

52 and even identified flux heterogeneity among Drosophila clades.

53 Here we explored the growth and functions of Drosophila cortex glia (which associate almost exclusive

54 at there is no evidence for the existence of Drosophila courtship song rhythms.

55 necrosis factor (TNF) superfamily homolog in Drosophila, Coxiella-infected flies exhibit reduced mort

56 Boundaries in the Bithorax complex (BX-C) of Drosophila delimit autonomous regulatory domains that dr

57 se Ash1l [(absent, small, or homeotic)-like (Drosophila)] develop epidermal hyperplasia and impaired

58 e show that restricting dietary yeast during Drosophila development can, depending upon the subsequen

59 P) or protein activator of PKR (PACT), while Drosophila Dicer-1 associates with Loquacious (Loqs).

60 Drosophila dorsal closure (DC), a morphogenetic process

61 , Manduca sexta, as well as the spotted wing drosophila, Drosophila suzukii.

62 ay be involved in regulating the lifespan of Drosophila during long-term hypoxia.

63 udy, we demonstrate that interaction between Drosophila E2F1 and Sd disrupts Yki/Sd complex formation

64 lular-matrix-based stiffness gradient in the Drosophila egg chamber instructs tissue elongation.

65 Studies of the Drosophila eggshell patterning provide unique insights i

66 me aspects of the morphological diversity of Drosophila eggshells, such as the prominent differences

67 precursors cover the ventral surface of the Drosophila embryo and larva and provide templates for cu

68 pathway specifies neuronal identities in the Drosophila embryo by regulating developmental patterning

69 larization in the anterior pole of the early Drosophila embryo to explore how cells compete for space

70 ng dorsal-ventral (DV) axis formation in the Drosophila embryo, we find that the poised enhancer sign

71 polarity during convergent extension in the Drosophila embryo.

72 essor of Hairless [Su(H)], in patterning the Drosophila embryo.

73 n and activation of Torso at the ends of the Drosophila embryo.

74 ection of a proneural cell fate in the early Drosophila embryo.

75 During Drosophila embryonic axis extension, actomyosin has a sp

76 regulation of temporal factor expression in Drosophila embryonic or larval neural progenitors.

77 Here we demonstrate that Drosophila embryos expressing catalytically deficient Tr

78 irst wave of de novo transcription in living Drosophila embryos using dual-fluorescence detection of

79 ws for the quantification of single mRNAs in Drosophila embryos, using commercially available smFISH

80 tivation approaches and live-cell imaging in Drosophila embryos, we dissect the role of condensin I i

81 Two such genes in Drosophila encode the enzymes dopa decarboxylase (Ddc) a

82 x metalloproteinase-1 (MMP-1), is induced in Drosophila ensheathing glia responding to severed axons.

83 ractions, we established stable and isogenic Drosophila epilines that carry alternative epialleles, a

84 signal-producing cells to form a gradient in Drosophila epithelia.

85 we examine Rab protein distributions during Drosophila epithelial tissue remodeling and show that Ra

86 Here, we explore how the Drosophila erecta even-skipped (eve) locus has evolved b

87 Through an RNAi screen in the developing Drosophila eye, we found that partial APC/C inactivation

88 Here, we show that purified Drosophila Fhod and human FHOD1 both accelerate actin as

89 Drosophila Fhod binds tightly to barbed ends, where it s

90 equirement for SOCE in neurons that regulate Drosophila flight bouts.

91 ion of APOL1 in vivo We generated transgenic Drosophila fly lines expressing the human APOL1 wild typ

92 study, we identified an interaction between Drosophila FOXO (dFOXO) and the zinc finger transcriptio

93 an and cognitive phenotypes displayed by the Drosophila fragile X model, and thus reveal a metabolic

94 these interactions in magnetically tethered Drosophila free to rotate about the yaw axis.

95 n spectra between WT and the Opn4-expressing Drosophila further indicated that large quantities of a

96 In the Drosophila FXS disease model, we found FMRP binds shrub

97 In testing circuit level defects in the Drosophila FXS model, we discovered a completely unexpec

98 In conclusion, Drosophila garland cell nephrocytes provide a model with

99 We report DGET, a Drosophila Gene Expression Tool ( www.flyrnai.org/tools/

100 el 3' termini, and reveal that two-thirds of Drosophila genes are subject to APA.

101 uman gene variant analysis; new uses for the Drosophila Genetic Reference Panel (DGRP) in detection o

102 Here, by using the power of Drosophila genetics in combination with electrophysiolog

103 promoters, enhancers, and insulators in the Drosophila genome.

104 -transposase-encoding mature mRNA isoform in Drosophila germ cells.

105 ted decline in neurotransmission through the Drosophila giant fiber system (GFS), a simple escape res

106 In Drosophila, graded expression of the maternal transcript

107 Drosophila have been used as model organisms to explore

108 The genetic techniques available in Drosophila have contributed to identify important roles

109 Using a Drosophila HD model, we find that nonaggregated pathogen

110 In a previously established Drosophila heart model for long-term hypoxia exposure, w

111 134 genes were tested in the Drosophila heart using RNAi-based gene silencing.

112 we demonstrate that depletion of the single Drosophila homolog dBRWD3 results in altered gene expres

113 rosine phosphatase (RPTP) and the only known Drosophila HSPG receptor, for promoting dendritic growth

114 riginally identified as an interactor of the Drosophila IkappaB factor Cactus and shown to play a rol

115 Drosophila imaginal disc growth factor 2 (IDGF2) is a me

116 e3-histone4 promoter direct HLB formation in Drosophila In addition, the CLAMP (chromatin-linked adap

117 Here we used transgenic Drosophila, in which the mouse OPN4 replaced the native

118 Experiments in Drosophila indicate that Ret is expressed both by enteri

119 In Drosophila infected with Mycobacterium marinum, mycobact

120 advances in understanding neuromodulation of Drosophila innate behaviors, with a special focus on fee

121 ing (IS) pathway revealed elevated levels of Drosophila insulin-like peptide 2 (Dilp2) in the IPCs an

122 ns, including those that secrete some of the Drosophila insulin-like peptides.

123 rrent tools developed for in vivo studies in Drosophila is limited by their incompatibility with exis

124 function of the interlocked feedback loop in Drosophila is to drive rhythmic transcription required f

125 Drosophila is widely used for the dissection of genetic

126 systematically tested the function of all 13 Drosophila JmjC genes.

127 This study shows that Drosophila KDM4A (dKDM4A), previously characterized as a

128 Here we show that Drosophila Kenny, the homolog of mammalian IKKgamma, is

129 we provide evidence for the usefulness of a Drosophila larva model to investigate genetic influence

130 circuit architecture of the visual system of Drosophila larvae by mapping the synaptic wiring diagram

131 ing long-term time-lapse imaging with intact Drosophila larvae, we found that dendrites grow into HSP

132 the lateral pentascolopidial (lch5) organ of Drosophila larvae-which plays a key role in propriocepti

133 ciceptive behavior and circuit physiology in Drosophila larvae.

134 tal system of cooperative behavior involving Drosophila larvae.

135 During Drosophila larval development, hematopoietic sites are i

136 Nedd4 protein regulates heart development in Drosophila Larval fly hearts overexpressing miR-1 have p

137 Drosophila larval tissues undergo endoreplication withou

138 We used CRISPR/Cas9 genome engineering of Drosophila legless (lgs) and human BCL9 and B9L to show

139 Here, we found that Drosophila leucine-rich pentatricopeptide repeat domain-

140 We show that 4E-BP determines Drosophila lifespan in the context of temperature change

141 stress is necessary and sufficient to extend Drosophila lifespan, and identify Phosphoglycerate Mutas

142 log, modulates the neural pathways that bias Drosophila males toward aggression.

143 These results suggest Drosophila MBD-containing proteins are required within t

144 Here, we report the Drosophila MBD-containing proteins, dMBD-R2 and dMBD2/3,

145 ethods on six model organisms, Mus musculus, Drosophila melanogaste, Arabidopsis thaliana, Oryza sati

146 cloned from Balanus improvisus (BiOctR) and Drosophila melanogaster (DmOctR), little is known about

147 sed assays with spatiotemporal resolution in Drosophila melanogaster (fruit fly) and Danio rerio (zeb

148 lyses of the homologs of RBPJ and L3MBTL3 in Drosophila melanogaster and Caenorhabditis elegans demon

149 that mutation of the SLC13A5 orthologues in Drosophila melanogaster and Caenorhabditis elegans promo

150 scription pattern, the invertebrate pattern (Drosophila melanogaster and Caenorhabditis elegans) prof

151 We used Drosophila melanogaster and Saccharomyces cerevisiae to

152 DNA haplotype into replicated populations of Drosophila melanogaster causes numerical population supp

153 Here, we show that in Drosophila melanogaster Cdk5 regulates basal autophagy,

154 ave been shown to bind to cholesterol/CHS in Drosophila melanogaster dopamine transporter.

155 Neural stem cells or neuroblasts in the Drosophila melanogaster embryo delaminate as single cell

156 Here, we report that Drosophila melanogaster females but not males adapt to h

157 Here we study Drosophila melanogaster from 'Evolution Canyon' in Israe

158 microbiome in determining this type of RI in Drosophila melanogaster has been proposed.

159 te TRAPP function in metazoans, we show that Drosophila melanogaster have two TRAPP complexes similar

160 Drosophila melanogaster is a natural host of parasitic w

161 Drosophila melanogaster is the paradigm for insect devel

162 ry neurons and reduced the survival of novel Drosophila melanogaster models of SCA35.

163 f acentric chromosome fragments generated in Drosophila melanogaster neuroblasts.

164 to identify the substrate specificity of the Drosophila melanogaster P-TEFb (DmP-TEFb) in vitro.

165 rica and Eurasia, hundreds of genomes from a Drosophila melanogaster population in Africa, and tens o

166 Drosophila melanogaster presents an advantageous model s

167 emonstrate that mate choice in the fruit fly Drosophila melanogaster results in the linear sorting of

168 CrPV(R146A) virus infection is attenuated in Drosophila melanogaster S2 cells and adult fruit flies a

169 A study in the fruit fly Drosophila melanogaster shows that satellite DNA, and co

170 ed the first new reference-quality genome of Drosophila melanogaster since its initial sequencing.

171 e Drosophila C virus (DCV) in populations of Drosophila melanogaster We found extensive allelic heter

172 We used Drosophila melanogaster wing vein and scutellar bristle

173 atasets and present results on datasets from Drosophila melanogaster wings and Schmidtae mediterranea

174 26 transformation-specific family repressors Drosophila melanogaster Yan and its human homolog TEL/ET

175 of bacterial colonization in the fruit fly (Drosophila melanogaster) gut.

176 ct insecticidal activity toward fruit flies (Drosophila melanogaster) indicates that Form II is more

177 In the fruit fly, Drosophila melanogaster, aversive olfactory learning for

178 In Drosophila melanogaster, DAT deficiency results in reduc

179 In the Malpighian (renal) tubule of Drosophila melanogaster, TA activates a transepithelial

180 This model is consistent with findings in Drosophila melanogaster, where gap genes were found to b

181 rthropods is best understood in the ovary of Drosophila melanogaster, where it acts to silence active

182 Here we report that ETH persists in adult Drosophila melanogaster, where it functions as an obliga

183 pathogenic mutations in ATP7 proteins using Drosophila melanogaster, which has a single orthologue o

184 n of the structure of the full length CTD of Drosophila melanogaster, which we conclude is a compact

185 opulations of visually responsive neurons in Drosophila melanogaster.

186 ian transcriptomes in heads of young and old Drosophila melanogaster.

187 our in many species, including the fruit fly Drosophila melanogaster.

188 of host lipid stores in the model arthropod Drosophila melanogaster.

189 Here, by characterizing Drosophila MIC60 mutants, we define its roles in vivo.

190 ermore, when comparing the DFE across yeast, Drosophila, mice, and humans, the average selection coef

191 omplementary theoretical models of the adult Drosophila midgut, a stem cell-based organ with known re

192 In Drosophila, mimicking phosphorylation at T3 decreased HT

193 Loss of Drosophila miR-1 produces defects in somatic muscle and

194 We found that Drosophila miR-263a downregulates the expression of epit

195 address this question, we generated a novel Drosophila model expressing human wild-type and ALS-caus

196 fp106 potently suppresses neurotoxicity in a Drosophila model of C9orf72 ALS.

197 eurodegeneration and locomotor deficits in a Drosophila model of C9ORF72-related disease.

198 We used a Drosophila model system and label-free proteomics to ide

199 their in vivo toxicity in a well controlled Drosophila model system, we find that all mutations test

200 Here we report genetic studies in a Drosophila model to define S100A4 effector functions tha

201 present study, we took the advantages of the Drosophila model to dissect the molecular pathways that

202 We have established a Drosophila model with hyperactivated Wnt signaling cause

203 In two Drosophila models of Huntington's disease, genetic knock

204 progression of neurodegenerative symptoms in Drosophila models of Parkinson's and Huntington's diseas

205 Therefore, in unmyelinated Drosophila motoneurons different functions of axonal and

206 We generated Pex19 Drosophila mutants, which recapitulate the hallmarks of

207 We conclude that the Drosophila nephrocyte can be used to elucidate clinicall

208 Drosophila nephrocytes and human podocytes share strikin

209 In Drosophila nephrocytes, deficiency of the Pals1 ortholog

210 itochondrial function are compromised in the Drosophila nervous system and SRS patient cells.

211 ge-scale chromatin remodelling occurs during Drosophila neural development.

212 strating a role of CFI in APA control during Drosophila neural development.

213 temporal patterning mechanisms discovered in Drosophila neural progenitors (neuroblasts) involve prog

214 Here we use Drosophila neural stem cells to elucidate the mechanisms

215 asymmetry during asymmetric cell division of Drosophila neuroblasts (NBs).

216 polarity during asymmetric cell division of Drosophila neuroblasts.

217 Our studies at the Drosophila neuromuscular junction indicate that many syn

218 ctivity-dependent synaptic plasticity at the Drosophila neuromuscular junction.

219 and trigger structural modifications at the Drosophila neuromuscular junction.

220 y-dependent pruning also occurs at embryonic Drosophila neuromuscular junctions (NMJs), where low-fre

221 to CHCs, and ectopic expression of HsOrs in Drosophila neurons imparts responsiveness to CHCs.

222 unction-mediated selective dendritic loss in Drosophila neurons.

223 presynaptically and postsynaptically at the Drosophila NMJ and that it is a presynaptic regulator of

224 have characterized C9orf72 pathology at the Drosophila NMJ and utilized several approaches to restor

225 ere we present a de novo atomic structure of Drosophila NOMPC determined by single-particle electron

226 e promoter-proximal pausing to DSIF-depleted Drosophila nuclear extracts.

227 Here, we examined Drosophila olfactory sensory neurons and found that inhi

228 f identified serotonergic neurons within the Drosophila olfactory system as a model to establish a fr

229 of the developmental programs underlying the Drosophila olfactory system harbor a disproportionate am

230 in a well-studied neoplastic tumor model in Drosophila, oncogenic mutations of the proto-oncogene Ra

231 sation of oskar mRNA to the posterior of the Drosophila oocyte defines where the abdomen and germ cel

232 maternal mito-nuclear incompatibility during Drosophila oogenesis has severe consequences for egg pro

233 morphogenesis of astrocyte-like glia in the Drosophila optic lobe, and through a RNAi screen, they i

234 dernourishment during the development of the Drosophila optic lobe.

235 By stimulating Drosophila ORNs in vivo with naturalistic and Gaussian s

236 ytosis as a functional read-out, we screened Drosophila orthologs of human monogenic causes of nephro

237 absence of the gene parcas that encodes the Drosophila orthologue of the SH3BP5 family of Rab11 guan

238 this, we first analyse the expression of the Drosophila orthologues of all mammalian CPA factors and

239 f Hop in the germ line nurse cells (GLKD) of Drosophila ovaries leads to activation of transposons.

240 cting RNA (piRNA)-targeted reporter assay in Drosophila ovary somatic sheet (OSS) cells [1].

241 chanistic insights into steroid signaling in Drosophila ovulation.

242 eat proteins and alleviates neurotoxicity in Drosophila, patient-derived neurons and neuronal cell mo

243 genes whose loss causes neurodegeneration in Drosophila photoreceptor neurons.

244 Drosophila photoreceptors respond to oscillating light o

245 Drosophila prefers a Saccharomyces-Acetobacter co-cultur

246 During neurogenesis, vertebrate and Drosophila progenitors change over time as they generate

247 ed gene expression changes in the developing Drosophila pupal nervous system.

248 OPN4 replaced the native Rh1 photopigment of Drosophila R1-6 photoreceptors, resulting in deformed rh

249 e X chromosome dosage compensation system in Drosophila, regulates gene activity by acetylating histo

250 We demonstrated that POMT mutations in Drosophila result in abnormal muscle contractions and ca

251 Here we show that Drosophila ring neurons-central brain neurons implicated

252 h ribosome footprint data from the aneuploid Drosophila S2 cell line, we report that the dose effect

253 , we found that Fkh mRNA was undetectable in Drosophila S2 cells, and M. sexta Fkh (MsFkh) interacted

254 TnBVank1 was stably expressed in polyclonal Drosophila S2 cells, apoptosis is induced.

255 er chromatids, and present a 3D model of the Drosophila SC based on these findings.

256 To explore this mechanism, we developed a Drosophila SCA5 model in which an equivalent mutant Dros

257 In Drosophila sensory organ precursors (SOPs), the core PCP

258 Despite this, recent work in Drosophila shows that mutation of a single miRNA locus (

259 of discrete unitary currents similar to the Drosophila single photon responses.

260 Here, we discovered that two Drosophila slit diaphragm proteins, orthologs of the hum

261 her, these data reveal miRNA diversity among Drosophila species and principles underlying their emerg

262 pected: at least 25 have arisen across three Drosophila species over the past 5.4 million years (1.67

263 ple, the behavioral adaptation of specialist Drosophila species to specific host plants can exhibit p

264 In-vivo Drosophila studies showed a genetic interaction of Parki

265 ved in an emerging agricultural insect pest, Drosophila suzukii, by creating a temperature-sensitive

266 xta, as well as the spotted wing drosophila, Drosophila suzukii.

267 Here, we establish the Drosophila system to study the m(6)A pathway.

268 e, we describe a novel injury assay in adult Drosophila that elicits widespread glial responses in th

269 STARR-seq identified two enhancer classes in Drosophila that interact with different core promoters:

270 olfactory receptor sensitivity regulation in Drosophila The phosphorylation state of Orco (S289) is a

271 In Drosophila, the mushroom body (MB) is critically involve

272 rms cytoplasmic inclusions when expressed in Drosophila, the mutation accelerates aggregation in vitr

273 In Drosophila, the translational repressor Bgcn is required

274 In Drosophila, this mechanism is required for synaptic plas

275 We also demonstrated the use of Drosophila to evaluate cardiac phenotypes resulting from

276 e have used a knock-out/knock-in strategy in Drosophila to generate a strain with hTau inserted into

277 rts an asymptomatic rhabdovirus infection in Drosophila to one that is lethal.

278 d function of dendritic L-type channels from Drosophila to vertebrates.

279 Using a Drosophila tumour model, we show that Egfr cooperates wi

280 Like mammalian neural stem cells, Drosophila type II neuroblasts utilize INPs to produce n

281 s seen in the vertebrate neural tube and the Drosophila ventral furrow.

282 The Drosophila visual system has become a premier model for

283 We found that in the Drosophila visual system, astrocyte-like medulla neuropi

284 rful comparisons have been those made to the Drosophila visual system, where a deeper understanding o

285 ct patterns of stimulation in motoneurons of Drosophila We found that the spacing effect is a phenome

286 In Drosophila, we demonstrate that blocking autophagy at an

287 Using forward genetic approaches in Drosophila, we find that reduction of AdamTS-A function

288 he small blocks of linkage disequilibrium in Drosophila, we obtain near base-pair resolution, resolvi

289 egation was reduced, and motor phenotypes in Drosophila were alleviated.

290 mperfect predictor of inclusion formation in Drosophila; while most mutations showed similar behavior

291 patial regulators are coordinated to control Drosophila wing development during metamorphosis.

292 Here we show that Drosophila wing disc cells carrying functionally unrelat

293 In the Drosophila wing disc, Hedgehog (Hh) produced by posterio

294 ng organ-scale intercellular Ca(2+) waves in Drosophila wing discs that are also observed in vivo dur

295 ll molecules differentially expressed in the Drosophila wing imaginal disc.

296 Cells throughout the Drosophila wing primordium typically show subcellular lo

297 Using the Drosophila wing, we demonstrate that temporal changes in

298 The first Wnt signaling ligand discovered, Drosophila Wingless (Wg; Wnt1 in mammals), plays crucial

299 that the genetic relationship is reversed in Drosophila, with Gen mutants having more severe defects

300 The Drosophila Y chromosome has been gradually acquiring gen