Bivalent behavior in Drosophila melanogaster males containing the In(1)sc 4Lsc8RX chromosome

The sex chromosome bivalent was examined in Drosophila melanogaster males possessing the In(1)sc ^4Lsc^8R X chromosome. Three-dimensional reconstructions from electron micrographs of serially cut thin sections were made. A large proportion of the kinetochores of In(1)sc ^4Lsc^8R/Y bivalents did not face opposite poles during metaphase I and anaphase I. This suggests that In(1)sc ^4Lsc^8R/Y bivalents may have difficulty achieving bipolar stability. Delay in achieving bipolar stability could contribute to the nondisjunctional behavior found in In(1)sc ^4Lsc^8R/Y males.     

The effects of Minute loci and the possible involvement of transfer-RNA in sex chromosome non-disjunction in the Drosophila melanogaster male

Summary This report shows that certain Minutes can greatly increase the frequency of sex chromosome non-disjunction in the In(1) sc ^4L sc ^8R, ^5E y/y ⁺Y system in the Drosophila melanogaster male. This effect is evaluated and discussed with special reference to the recent finding that the Minutes may be deficiencies of transfer RNA loci.     

Fine-Structure Analysis and Genetic Organization at the Base of the X Chromosome in DROSOPHILA MELANOGASTER

Genetic organization at the base of the X chromosome was studied through the analysis of X-ray-induced deficiencies. Deficiencies were recovered so as to have a preselected right end "anchored" in the centric heterochromatin to the right of the su(f) locus. "Free" ends of deficiencies occurred at any of 22 intervals in Section 20 and in the proximal portion of Section 19 of Bridges' (1938) polytene chromosome map. The distribution of 130 such free ends of deficiencies induced in normal, In(1)sc ⁸, and In(1)w^m4 chromosomes suggests that on the single section level, genes are flanked by "hot" or "cold" sites for X-ray-induced breaks, and that occurrence of the hot spots is dependent on their interaction with the fixed-end sites in the centric heterochromatin. In the light of these results, it is argued that long heterochromatic sequences separate the relatively few genes in Section 20, and thus endow it with several characteristics typical of heterochromatic regions. Section 20 is considered to be a transition region between the mostly heterochromatic and mostly euchromatic regions of the X chromosome; the differences between them are suggested as being merely quantitative.     

The centric region of the X chromosome rDNA functions in male meiotic pairing in Drosophila melanogaster

In Drosophila melanogaster males, sex chromosome pairing at meiosis is ensured by so-called pairing site(s) located discretely in the centric heterochromatin. The property of the pairing sites is not well understood. Recently, an hypothesis has been proposed that 240 bp repeats in the nontranscribed spacer region of rDNA function as the pairing sites in male meiosis. However, considerable cytogenetic evidence exists that is contrary to this hypothesis. Hence, the question is whether the chromosomal rDNA clusters, in which a high copy number of 240 bp repeats exists, are involved in the pairing. In order to resolve the problem we X-rayed Drosophila carrying the X chromosome inversion In(1)sc ^V2L sc ^8R and generated free, mini-X chromosomes carrying a substantial amount of rDNA. We defined cytogenetically the size of the mini-chromosomes and studied their meiotic behavior. Our results demonstrate that the heterochromatin at the distal end of the inversion, whose length is approximately 0.4 times that of the fourth chromosome, includes a meiotic pairing site in the male. We discuss the cytological location of the pairing site and the possible role of rDNA in meiotic pairing.     

FISH analysis of<Emphasis Type="Italic"> Drosophila melanogaster</Emphasis> heterochromatin using BACs and<Emphasis Type="Italic"> P</Emphasis> elements

The heterochromatin of chromosomes 2 and 3 of Drosophila melanogaster contains about 30 essential genes defined by genetic analysis. In the last decade only a few of these genes have been molecularly characterized and found to correspond to protein-coding genes involved in important cellular functions. Moreover, several predicted genes have been identified by annotation of genomic sequence that are associated with polytene chromosome divisions 40, 41 and 80 but their locations on the cytogenetic map of the heterochromatin are still uncertain. To expand our current knowledge of the genetic functions located in heterochromatin, we have performed fluorescence in situ hybridization (FISH) mapping to mitotic chromosomes of nine bacterial artificial chromosomes (BACs) carrying several predicted genes and of 13 P element insertions assigned to the proximal regions of 2R and 3L. We found that 22 predicted genes map to the h46 region of 2R and eight map to the h47 regions of 3L. This amounts to at least 30 predicted genes located in these heterochromatic regions, whereas previous studies detected only seven vital genes. Finally, another 58 genes localize either in the euchromatin-heterochromatin transition regions or in the proximal euchromatin of 2R and 3L. Edited by: B. McKeeN. Corradini and F. Rossi contributed equally to this work     

Meiosis in Drosophila melanogaster

Chromosome pairing during meiosis I in D. melanogaster males was investigated ultrastructurally by examining complete bivalents in electron micrographs of serial thin sections. The XY bivalent is characterized by the presence of unique material located between the two half-bivalents at the site of synapsis. The material has a fibrillar appearance and is less electron dense than the surrounding chromatin. YY bivalents in XYY males and XY bivalents containing the X chromosome, In(1)sc ^4Lsc^8R, where the pairing sites of the X chromosome are inverted and partially deleted also possess this material. The material is not associated with autosomal bivalents and may represent a morphological manifestation of the hypothetical cohesive elements (collochores) which are thought to function in conjunction of the X and Y chromosomes (Cooper, 1964).     

An analysis of white-mottled mutants inDrosophila hydei,with observations on X-Y exchanges in the male

Chromosomes and phenotypes of four different sex-linkedwhite-mottled mutants of the position-effect variogation type were studied. Three mutants (w ^m1,w ^m2,w ^m3) are X-chromosomal rearrangements which shift the w⁺ locus into a position close to heterochromatin, but which have different ouchromatic and heterochromatic breaks. The fourth, a spontaneous derivative ofw ^m1, is an insertional duplication of part of the X chromosome, including thew ⁺ andN ⁺loci. The duplicated segment is inserted into the distal part of the long arm of the heterochromatic Y chromosome. It is designated,w ^m CoY, orXw ^m Co when transferred to the X chromosome.Three chromosomal types (w ^m1,w ^m CoY) and (Xw ^m Co) having the same cuchromatic break near thew ⁺ locus, cause large-spotted eyes whereas two others (w ^m2,w ^m3) produce a popper-and-salt type of mottling. From the position of the various eu- and heterochromatic breaks, it appears that the distance of thew ⁺ locus to the point of reunion with heterochromatin, rather than the amount or type of adjoining heterochromatin, dietates the phenotypic action of the displacedw ⁺ locus, in the sense of a spreading effect on two proposed functional subunits within thew ⁺ locus.The pigmentation background against which the mottling effect is produced, i.e., a givenw-allele with its characteristic colour, or other eye colour mutations, does not seem to affect the type of mottling. Drosopterins and ommochromes react in the same way to modifing factors like temperature and supernumerary Y chromosomes. Two mutants (w ^m2 andw ^m CoY) while reacting in the same manner to Y chromosomes showed an opposite temperature response.By exchange between the heterochromatin of the Y and X chromosome inw/w ^m CoY males thew ^m Co duplication was transferred between the sex chromosomes with a certain regularity. It is not yet known wether the exchanges are mitotic or meiotic in origin but their heterochromatic nature has been demonstrated cytologically.     

Genetic Analysis of the Centromeric Heterochromatin of Chromosome 2 of DROSOPHILA MELANOGASTER: Deficiency Mapping of Ems-Induced Lethal Complementation Groups

Until recently, little was known of the genetic constitution of the heterochromatic segments of the major autosomes of Drosophila melanogaster . Our previous report described the genetic dissection of the proximal, heterochromatic region of chromosome 2 of Drosophila melanogaster by means of a series of overlapping deficiencies generated by the detachment of compound second autosomes (Hilliker and Holm 1975). Analysis of these deficiencies by inter se complementation, pseudo-dominance tests with proximal mutations and allelism tests with known deficiencies provided evidence for the existence of at least two loci between the centromere and the light locus in 2L and one locus in 2R between the rolled locus and the centromere. These data in conjunction with cytological observations demonstrated that light and rolled and three loci lying between them are located within the proximal heterochromatin of the second chromosome.——The present report describes the further analysis of this region through the induction with ethyl methanesulphonate (EMS) of recessive lethals allelic to the 2L and 2R proximal deficiencies associated with the detachment products. Analysis of the 118 EMS-induced recessive lethals and visible mutations recovered provided evidence for seven loci in the 2L heterochromatin and six loci in the 2R heterochromatin, with multiple alleles being obtained for most sites. Of these loci, one in 2L and two in 2R fall near the heterochromatic-euchromatic junctions of 2L and 2R respectively. None of the 113 EMS lethals behaved as a deficiency, implying that the heterochromatic loci uncovered in this study represent nonrepetitive cistrons. Thus functional genetic loci are found in heterochromatin, albeit at a very low density relative to euchromatin.     

Sex Chromosome Meiotic Drive Systems in DROSOPHILA MELANOGASTER I. Abnormal Spermatid Development in Males with a Heterochromatin-Deficient X Chromosome (sc4sc8)

The meiotic drive characteristics of the In(1)sc^4Lsc^8R/Y system have been examined by genetic analysis and by light and electron microscopy. sc⁴sc⁸/Y males show a direct correlation between nondisjunction frequency and meiotic drive. Temperature-shift experiments reveal that the temperature-sensitive period for nondisjunction is at meiosis, whereas that for meiotic drive has both meiotic and post-meiotic components. Cytological analyses in the light and electron microscopes reveal failures in spermiogenesis in the testes of sc⁴sc⁸ males. The extent of abnormal spermatid development increases as nondisjunction becomes more extreme.     

X-4 Translocations and Meiotic Drive in Drosophila melanogaster Males: Role of Sex Chromosome Pairing

Males carrying certain X-4 translocations exhibit strongly skewed sperm recovery ratios. The X^P4^D half of the translocation disjoins regularly from the Y chromosome and the 4^PX^D half disjoins regularly from the normal 4. Yet the smaller member of each bivalent is recovered in excess of its pairing partner, apparently due to differential gametic lethality. Chromosome recovery probabilities are multiplicative; the viability of each genotype is the product of the recovery probability of its component chromosomes. Meiotic drive can also be caused by deficiency for X heterochromatin. In(1)sc^4Lsc^8R males show the same size dependent chromosome recoveries and multiplicative recovery probabilities found in T(1;4)B^S males. Meiotic drive in In(1)sc^4Lsc^8R males has been shown to be due to X-Y pairing failure. Although pairing is regular in the T(X;4) males, the striking phenotypic parallels suggest a common explanation. The experiments described below show that the two phenomena are, in fact, one and the same. X-4 translocations are shown to have the same effect on recovery of independently assorting chromosomes as does In(1)sc^4Lsc^8R. Addition of pairing sites to the 4^PX^D half of the translocation eliminates drive. A common explanation—failure of the distal euchromatic portion of the X chromosome to participate in X:Y meiotic pairing—is suggested as the cause for drive. The effect of X chromosome breakpoint on X-4 translocation induced meiotic drive is investigated. It is found that translocations with breakpoints distal to 13C on the salivary map do not cause drive while translocations broken proximal to 13C cause drive. The level of drive is related to the position of the breakpoint—the more proximal the breakpoint the greater the drive.     

Heterochromatin and histone phosphorylation

Histone phosphorylation and nuclear structure have been compared in cultured cell lines of two related species of deer mice, Peromyscus crinitus and Peromyscus eremicus, which differ greatly in their heterochromatin contents but which contain essentially the same euchromatin content. Flow microfluorometry measurements indicated that P. eremicus contained 36% more DNA than did P. crinitus, and C-band chromosome staining indicated that the extra DNA of P. eremicus existed as constitutive heterochromatin. Two striking differences in interphase nuclear structure were observed by electron microscopy. Peromyscus crinitus nuclei contained small clumps of heterochromatin and a loose, amorphous nucleolus, while P. eremicus nuclei contained large, dense clumps of heterochromatin and a densely structured, well defined, nucleolonema form of nucleolus. Incorporation of ³²PO₄ into histones indicated that the steady-state phosphorylation of H1 was identical in P. crinitus and P. eremicus cells. In contrast, the phosphorylation rate of H2a was 58% greater in the highly heterochromatic chromatin of P. eremicus cells than in the lesser heterochromatic chromatin of P. crinitus cells, suggesting an involvement of H2a phosphorylation in heterochromatin structure. It is suggested that the three histone phosphorylations related to cell growth (H1, H2a, and H3) may be associated with different levels of chromatin organization: H1 interphase phosphorylation with some submicroscopic (molecular) level of organization, H2a phosphorylation with a higher level of chromatin organization found in heterochromatin, and H3 and H1 superphosphorylation with the highest level of chromatin organization observed in condensed chromosomes.     

The effect of JIL-1 on position-effect variegation is proportional to the total amount of heterochromatin in the genome

In this study we have taken advantage of recent whole genome sequencing studies that have determined the DNA content in the heterochromatic regions of each Drosophila chromosome to directly correlate the effect on position-effect variegation of a pericentric insertion reporter line, 118E-10 with the total amount of heterochromatic DNA. Heterochromatic DNA levels were manipulated by adding or subtracting a Y chromosome as well as by the difference in the amount of pericentric heterochromatin between the X and Y chromosome. The results showed a direct, linear relationship between the amount of heterochromatic DNA in the genome and the expression of the w marker gene in the 118E-10 pericentric reporter line and that increasing amounts of heterochromatic DNA resulted in increasing amounts of pigment/gene activity. In Drosophila heterochromatic spreading and gene silencing is counteracted by H3S10 phosphorylation by the JIL-1 kinase, and we further demonstrate that the haplo-enhancer effect of JIL-1 is proportional to the amount of total heterochomatin, suggesting that JIL-1's activity is dynamically modulated to achieve a more or less constant balance depending on the levels of heterochromatic factors present.     

Cytogenetical localization of Zygotic hybrid rescue (Zhr), a Drosophila melanogaster gene that rescues interspecific hybrids from embryonic lethality

Hybrid females from crosses between Drsophila melanogaster males and females of its sibling species, D. simulans, D. mauritiana, or D. sechellia die as embryos. This lethality is believed to be caused by incompatibility between the X chromosome of D. melanogaster and the maternal cytoplasm. Zygotic hybrid rescue (Zhr) prevents this embryonic lethality and has been cytogenetically mapped to a proximal region of the X chromosome of D. melanogaster, probably in the centromeric heterochromatin. We have carried out high resolution cytological mapping of Zhr using deficiencies and duplications of the X heterochromatin. Deletions of the Zhr ⁺ gene from the hybrid genome exhibit the Zhr phenotype. On the contrary, addition of the wild-type gene to the hybrid genome causes embryonic lethality, regardless of sex. The Zhr locus has been narrowed down to the region covered by Dp(1;f)1162 but not covered Dp(1;f)1205, a chromosome carrying a duplication of heterochromatin located slightly distal to the In(1)sc ⁸ heterochromatic breakpoint.     

Are dicentric anaphase bridges formed by somatic recombination in X chromosome inversion heterozygotes of Drosophila melanogaster?

Summary Mitotic recombination has been induced with X-rays in Drosophila melanogaster larvae and assayed later as twin mosaic spots on the adult tergites. With the use of the In(1)sc ^4L sc ^8R chromosome which lacks the nucleolar organizer and is marked with yellow (y) indirect evidence was obtained that mitotic recombination between ring and rod chromosomes results, in a majority of cases, in XO spots, bearing the rod-X only. This was concluded from the relative scarcity and small sizes of y NO^- spots (uncovering the sc ⁴ sc ⁸ chromosome), compared to control sisters bearing an extra Y chromosome with its NO locus. Thus, dicentric chromatid bridges formed by mitotic recombination between the ring and rod chromosomes are probably eliminated at the next division.In In(1)sc ⁴ sc ⁸/f^36a (rod/rod) females, no effect of the Y chromosome on the frequency and sizes of cross-over spots was observed. Either any dicentric chromatid bridges formed by recombination between inverted rod chromosomes fragment at division, with a centromeric piece going to each pole, or such bridges are not usually formed by recombination. The latter case would indicate that somatic pairing of homologues is not accurate in X chromosome inversion heterozygotes and consequently, that recombination yields aneuploid cells.Additional studies are cited which indicate that X chromosome heterozygotes for entire arm inversions may not pair in the typical loop at the time of mitotic recombination.Supported in part by U.S.P.H.S. Grant GM 17096 to J.R.M., and the Kredit zur Förderung des akademischen Nachwuchses an der Universität Zürich to R.N.     

Cytogenetical localization of Zygotic hybrid rescue (Zhr), a Drosophila melanogaster gene that rescues interspecific hybrids from embryonic lethality

Hybrid females from crosses between Drsophila melanogaster males and females of its sibling species, D. simulans, D. mauritiana, or D. sechellia die as embryos. This lethality is believed to be caused by incompatibility between the X chromosome of D. melanogaster and the maternal cytoplasm. Zygotic hybrid rescue (Zhr) prevents this embryonic lethality and has been cytogenetically mapped to a proximal region of the X chromosome of D. melanogaster, probably in the centromeric heterochromatin. We have carried out high resolution cytological mapping of Zhr using deficiencies and duplications of the X heterochromatin. Deletions of the Zhr ⁺ gene from the hybrid genome exhibit the Zhr phenotype. On the contrary, addition of the wild-type gene to the hybrid genome causes embryonic lethality, regardless of sex. The Zhr locus has been narrowed down to the region covered by Dp(1;f)1162 but not covered Dp(1;f)1205, a chromosome carrying a duplication of heterochromatin located slightly distal to the In(1)sc ⁸ heterochromatic breakpoint.     

The mechanism of Na+ transport by rabbit urinary bladder

Summary The mechanism of Na⁺ transport in rabbit urinary bladder has been studied by microelectrode techniques. Of the three layers of epithelium, the apical layer contains virtually all the transepithelial resistance. There is radial cell-to-cell coupling within this layer, but there is no detectable transverse coupling between layers. Cell coupling is apparently interrupted by intracellular injection of depolarizing current. The cell interiors are electrically negative to the bathing solutions, but the apical membrane of the apical layer depolarizes with increasingI _sc. Voltage scanning detects no current sinks at the cell junctions or elsewhere. The voltage-divider ratio, , (ratio of resistance of apical cell membrane,R _a, to basolateral cell membrane,R _b) decreases from 30 to 0.5 with increasingI _sc, because of the transportrelated conductance pathway in the apical membrane. Changes in effective transepithelial capacitance withI _sc are predicted and possibly observed. The transepithelial resistance,R _t, has been resolved intoR _a, R_b, and the junctional resistance,R _j, by four different methods: cable analysis, resistance of uncoupled cells, measurements of pairs of (R _t, ) values in the same bladder at different transport rates, and the relation betweenR _t andI _sc and between andI _sc.R _j proves to be effectively infinite (nominally 300 k F) and independent ofI _sc, andR _a decreases from 154 to 4 k F with increasingI _sc. In the resulting model of Na⁺ transport in tight epithelia, the apical membrane contains an amiloride-inhibited and Ca⁺⁺-inhibited conductance pathway for Na⁺ entry; the basolateral membrane contains a Na⁺–K⁺-activated ATPase that extrudes Na⁺; intracellular (Na⁺) may exert negative feedback on apical membrane conductance; and aldosterone acts to stimulate Na⁺ entry at the apical membrane via the amiloride-sensitive pathway.     

A Distinct Type of Heterochromatin at the Telomeric Region of the Drosophila melanogaster Y Chromosome

Heterochromatin assembly and its associated phenotype, position effect variegation (PEV), provide an informative system to study chromatin structure and genome packaging. In the fruit fly Drosophila melanogaster, the Y chromosome is entirely heterochromatic in all cell types except the male germline; as such, Y chromosome dosage is a potent modifier of PEV. However, neither Y heterochromatin composition, nor its assembly, has been carefully studied. Here, we report the mapping and characterization of eight reporter lines that show male-specific PEV. In all eight cases, the reporter insertion sites lie in the telomeric transposon array (HeT-A and TART-B2 homologous repeats) of the Y chromosome short arm (Ys). Investigations of the impact on the PEV phenotype of mutations in known heterochromatin proteins (i.e., modifiers of PEV) show that this Ys telomeric region is a unique heterochromatin domain: it displays sensitivity to mutations in HP1a, EGG and SU(VAR)3-9, but no sensitivity to Su(z)2 mutations. It appears that the endo-siRNA pathway plays a major targeting role for this domain. Interestingly, an ectopic copy of 1360 is sufficient to induce a piRNA targeting mechanism to further enhance silencing of a reporter cytologically localized to the Ys telomere. These results demonstrate the diversity of heterochromatin domains, and the corresponding variation in potential targeting mechanisms.     

Heterochromatic Effects on the Behavior of Reversed Acrocentric Compound-X Chromosomes in DROSOPHILA MELANOGASTER

Previous studies of reversed acrocentric compound-X chromosomes suggested peculiar influences of heterochromatin on both the synthesis and meiotic behavior of such compunds. It seemed, with respect to synthesis, that the long arm of the Y chromosome on an X.Y(L) chromosome was necessary in order for the heterochromatic exchange giving rise to reversed acrocentrics to occur, even though Y(L) itself did not participate in the compound-generating event. With respect to behavior, the resulting compounds appeared, presumably as a consequence of their singular generation, to contain an interstitial heterochromatic region that caused the distribution of exchanges between the elements of the compound to be abnormal (many zero and two-exchange tetrads with few, if any, single-exchange tetrads). Removing the intersititial heterochromatin (or, curiously, appending Y(L) as a second arm of the compound) eliminated the recombinational anomalies and resulted in typical tetrad distributions.--We provide evidence that these peculiarities, while presumably real, were likely the consequence of a special X.Y(L) chromosome that was used to synthesize the reversed acrocentrics examined in the early studies and are not general properties of either reversed acrocentric compounds or of interstitial heterochromatin. However, we show that specific heterochromatic regions do, in fact, profoundly influence the behavior of (apparently all) reversed acrocentric compound-X chromosomes. In particular, we demonstrate that specific portions of the Y chromosome and of the basal X-chromosome heterochromatin, when present as homologs for reversed acrocentric compounds, markedly and coordinately increase both the frequency of exchange between the elements of the compound and the fertility (egg production) of compound-bearing females. It is, we suppose, some aspect of this heterochromatic effect, produced by the special X.Y(L) chromosome, that caused the earlier-analyzed compounds to exhibit the observed anomalies.     

Chromosome plasticity in Ctenomys (Rodentia Octodontidae): chromosome 1 evolution and heterochromatin variation

A chromosome 1 (Cr1) pericentric inversion is described in six of seven species in the genus Ctenomys (tuco-tucos) from Uruguay. The inversion was inferred from G-band analyses of subtelocentric Cr1 hypothesised to be derived from the ancestral metacentric condition. Cr1 varies across species in heterochromatin amount and localisation including a metacentric chromosome without positive C-bands in C. torquatus, a subtelocentric chromosome with heterochromatic short arms in C. rionegrensis, and a subtelocentric chromosome negative after C-banding in five of the species analysed here. Pachytene chromosomes from C. rionegrensis, a species with the highest heterochromatin content, and C. torquatus, one of the species with the lowest heterochromatin content, were analysed in order to assess possible mechanisms of heterochromatin evolution. This analysis revealed the presence of three heterochromatic chromocenters in C. rionegrensis where bivalents converge, while in C. torquatus only one chromocenter was observed. In both species, highly repetitive DNA was observed, localised in chromocenters after “in situ” hybridisation. Heterochromatin associated protein M31 was localised in chromocenters of both species after immuno-detection. The spread of heterochromatin in Ctenomys chromosomes could be produced by chromatin exchanges at the chromocenter level. We propose the exchange of this DNA associated proteins between non-homologous chromosomes in pachytene to be the responsible for the spread of heterochromatin through the karyotypes of species like C. rionegrensis     

Respirable powder formulation of a shortened vasoactive intestinal peptide analog for treatment of airway inflammatory diseases

The aim of present study was to develop a respirable powder (RP) of a shortened vasoactive intestinal peptide (VIP) analog for inhalation. VIP and C‐terminally truncated VIP analogs were synthesized with a solid‐phase method. A structure‐activity relationship (SAR) study was carried out in terms with binding and relaxant activities of the peptides. Prepared RP formulation of a shortened VIP analog was physicochemically characterized by morphological, in vitro aerodynamic, and pharmacological assessments. The SAR study demonstrated that the N‐terminal 23 amino acid residues were required for biological activity of VIP. Upon chemical modification of VIP(1–23), [R^{15, 20, 21}, L¹⁷]‐VIP(1–23) was newly developed, which had higher binding activity in rat lung and smooth muscle relaxant effect in mouse stomach than VIP(1–23). The [R^{15, 20, 21}, L¹⁷]‐VIP(1–23)‐based RP, [R^{15, 20, 21}, L¹⁷]‐VIP(1–23)/RP, exhibited fine in vitro inhalation performance. Airway inflammation evoked by sensitization of antigen in rats was attenuated by pre‐treatment with the [R^{15, 20, 21}, L¹⁷]‐VIP(1–23)/RP at a dose of 50 μg‐[R^{15, 20, 21}, L¹⁷]‐VIP(1–23)/rat as evidenced by a 70% reduction of recruited inflammatory cells in bronchoalveolar lavage fluid. On the basis of these results, [R^{15, 20, 21}, L¹⁷]‐VIP(1–23)/RP might be a promising agent for treatment of airway inflammatory diseases.