The 3′ Region of the Chicken Hypersensitive Site-4 Insulator Has Properties Similar to Its Core and Is Required for Full Insulator Activity

Chromatin insulators separate active transcriptional domains and block the spread of heterochromatin in the genome. Studies on the chicken hypersensitive site-4 (cHS4) element, a prototypic insulator, have identified CTCF and USF-1/2 motifs in the proximal 250 bp of cHS4, termed the “core”, which provide enhancer blocking activity and reduce position effects. However, the core alone does not insulate viral vectors effectively. The full-length cHS4 has excellent insulating properties, but its large size severely compromises vector titers. We performed a structure-function analysis of cHS4 flanking lentivirus-vectors and analyzed transgene expression in the clonal progeny of hematopoietic stem cells and epigenetic changes in cHS4 and the transgene promoter. We found that the core only reduced the clonal variegation in expression. Unique insulator activity resided in the distal 400 bp cHS4 sequences, which when combined with the core, restored full insulator activity and open chromatin marks over the transgene promoter and the insulator. These data consolidate the known insulating activity of the canonical 5′ core with a novel 3′ 400 bp element with properties similar to the core. Together, they have excellent insulating properties and viral titers. Our data have important implications in understanding the molecular basis of insulator function and design of gene therapy vectors

Streptocephalus spinier Gurney 1906

Streptocephalus spinier Gurney, 1906 Materials investigated. Akavedu (Andrapradesh) (16 ° 20 N, 80 ° 27 E). Accession numbers are DZ/NM/FS/ 151. Measurements. 7 males (7.5–11.6); 5 females (6.3–10.5). Description: male First antennae longer than eye and peduncle (Fig. 5 A). Frontal appendage is sub­cylindrical, long, and divided into two segments. Each branch has a long, stout ventrally curved process (Fig. 5 C) which has small papillae on the ventral side. Just beneath the frontal appendage, a sharp, conical spine­like structure is observed basally between the second antennae (Fig. 5 B). Basal joint of second antennae has a slender, long antennomere at its distal end (Fig. 5 B). Antennal appendage show three protuberances on its medial surface (Fig. 5 C). Hand of second antennae is short and broad. Thumb is simple, long, slender, slightly curved, tapering towards the end and longer than the finger (Fig. 5 D). A small bulge spur is present at the base of thumb (Fig. 5 E). Angle between proximal and distal region of thumb is approximately 150 °. Finger is broad, distally slender, approximately two­third of the length the of thumb and with large, acute triangular tooth at its base. Mature adult has 11 pedigerous thoracic segments followed by genital segment. Seven apodous abdominal segments, with spines on the dorso­lateral side (Fig. 5 F). Penes is long and coiled, the basal and non­retractile part has a posterior conical projection with spines on its surface (Fig. 5 G, H, I). The retractile part of penes each has three rows of longitudinal spines (Fig. 5 J). Cercopods are long and bear small stiff setae proximally and long fleshy spines distally (Fig. 5 L). The number of setae and spines, however, differ considerably between individuals. Female. Spiniform rostrum and frontal appendage are absent in females. The second antennae are reduced and blade­like. Abdominal segments are devoid of spines. The ovisac is narrow, cylindrical in shape and extends to fourth abdominal segment (Fig. 5 K). Cercopods bear uniform, long thin setae and are devoid of fleshy spines. Egg. Cyst surface is covered with a series of pentagonal structures, with raised ridges pointing upwards (looks like spines) (Fig. 5 I), and covered with small pores on their surfaces (Figs. 5 M, N). Remarks. Streptocephalus spinifer Gurney, 1906 differs from other species in the following respects: the male has a frontal appendage; the second antennae of the male has a thumb and a finger; but no separate posterior or anterior ramus in hand; abdominal segments have spines; cercopods bears stiff setae and long fleshy spines. This species is smaller and slender than the other species. Cyst surface is pentagonal polygons with centered raised ridges.Published as part of Velu, Chinavenmeni S & Munuswamy, Natesan, 2005, Updated diagnoses for the Indian species of Streptocephalus (Crustacea: Branchiopoda: Anostraca), pp. 33-48 in Zootaxa 1049 on pages 42-44, DOI: 10.5281/zenodo.16994

Streptocephalus echinus Bond 1934

Streptocephalus echinus Bond, 1934 Material examined. Guntur (16 ° 18 N, 80 ° 29 E), Poondi (13 °02N, 80 ° 10 E), Chengleput (12 ° 42 N, 80 °01E). Accession numbers are DZ/NM/FS/ 130 to 132. Measurements: 13 males (14.6–16.8); 26 females (14.2–15.6). Description: Male­First antennae project laterally and point towards posterior end (Fig. 3 A, D). Second antennae have sub­cylindrical proximal segment, distal segment slender, directed posterior medially. Antennal appendage long, peduncle stout, “S” curved, anterio­lateral sub­crenulate papillae are absent (Fig. 3 B, C). Peduncle bears a lateral row of slender spines at the distal curve (Fig. 3 D). Cheliform hand elongate; thumb shorter than peduncle, bears an arcuate spur and no shoulder opposite the spur. Finger as long as peduncle, bifid, with posterior ramus serrated at basal and distal end and arcing interiorly (Figs. 3 B, C). Anterior ramus spinose arranged as series of long spines (Figs. 3 B). Bases of proximal portion of penes each with a lateral linguiform projection, proximal nonretractile part of penes bears an anteriorly curved medial projection with spines on the anterior surface (Fig. 3 E). Cercopods are lanceolate, setiferous to tip with fine setae. Female Second antennae are simple, flat, rounded at the tip (Fig. 3 D). Brood pouch slender, extends to third and forth abdominal segment (Fig. 3 F). Cyst The cyst surface is covered with series of pentagonal shaped polygons. The ridges are raised, surface covered with pores and centered fields are smooth and depressed without pores (Figs. 3 G, H). Remarks Streptocephalus echinus Bond, 1934 can be differentiated from others based on the following structures: The second antennae of the male has serration at the anterior part of the anterior ramus; the anterior­lateral subcranulate papillae are absent; the thumb is shorter than the peduncle and finger and it has no shoulder on the thumb. The cyst surface is covered with pentagonal shaped polygons and smooth, depressed centered field with no pores.Published as part of Velu, Chinavenmeni S & Munuswamy, Natesan, 2005, Updated diagnoses for the Indian species of Streptocephalus (Crustacea: Branchiopoda: Anostraca), pp. 33-48 in Zootaxa 1049 on page 39, DOI: 10.5281/zenodo.16994

Streptocephalus longimanus Bond 1934

Streptocephalus longimanus Bond, 1934 Materials investigated. Kovalam (13 °04N, 80 ° 18 E), Chengleput (12 ° 42 N, 80 °01E). Measurements. 9 males (15.3–16.9); 5 females (14.2–15.3). Accession numbers are DZ/NM/FS/ 141–142. Description: Male­First antennae is slender, coiled at distal end and hidden under the compound eye (Fig. 4 A). Second antennae directed posteriomedially, proximal segment sub­cylindrical, distal segment slender. Antennal appendage long with five anterio­lateral sub­crenulate papillae proximal to the first curve, the first one being large compared to others (Fig. 4 B). Peduncle stout, S­curved, longer than second antennal proximal segment, and bears a lateral row of slender spines at the distal curve (Fig. 4 B, D). “Hand” elongate cheliform; thumb longer and equal to finger, bearing an arcuate spur, and no shoulder opposite the spur (Fig. 4 C). Finger is long, bifid with posterior ramus smooth and arcing anteriorly. Anterior ramus of finger with spines arranged as a series of shorter spines (Fig. 4 C, D). Thoracic and abdominal appendages are smooth. Penes have lateral linguiform projections at the base of proximal portion. Proximal non­retractile part of penes bears an anteriorly curved medial projection with no spines on the anterior surface (Fig. 4 G). Cercopods are lanceolate, setiferous to tip with fine setae and a groove in the middle on the entire length (Fig. 4 I). Female. Second antennae is simple, flat and rectangular (Fig. 4 E, F). Brood pouch extends to the forth abdominal segment with a blue streak on its ventral surface (Fig. 4 H). Cyst The cyst surface is covered with a series of pentagonal polygons. The ridges are raised, broad and with centered depressed fields (Figs. 4 J, K). The surface is covered with small pores both in ridges and depressed fields (Fig. 4 K). Remarks. Streptocephalus longimanus Bond, 1934 can be separated from other species on the following characters: The second antennae of male has small spines on the posterior ramus, the thumb being equal to the finger; the penes has medial projections with a smooth surface; cercopods lanceolate with a groove. A bluish streak on the brood pouch is seen in the female. Cyst surface is covered with pentagonal polygons and has pores all over.Published as part of Velu, Chinavenmeni S & Munuswamy, Natesan, 2005, Updated diagnoses for the Indian species of Streptocephalus (Crustacea: Branchiopoda: Anostraca), pp. 33-48 in Zootaxa 1049 on pages 39-42, DOI: 10.5281/zenodo.16994

FIGURE 1. Streptocephalus dichotomus BAIRD. A in Updated diagnoses for the Indian species of Streptocephalus (Crustacea: Branchiopoda: Anostraca)

FIGURE 1. Streptocephalus dichotomus BAIRD. A. Male, lateral view of head. B. Male antennae, lateral view. C. Medial view of second antennae. D. Female, ventral view of head. E. Ventral view of male genital region, arrow showing the spines on the protruberances. F. Protracted penis G. Female abdomen, lateral view of brood­pouch. H. Higher magnification of the terminal end of ovisac. I. Cysts. J. Details of cyst surface with ridge, depression and pores. K. Male, Telson

Gfi1 integrates progenitor versus granulocytic transcriptional programming

In patients with severe congenital neutropenia (SCN) and mice with growth factor independent-1 (Gfi1) loss of function, arrested myeloid progenitors accumulate, whereas terminal granulopoiesis is blocked. One might assume that Gfi-null progenitors accumulate because they lack the ability to differentiate. Instead, our data indicate that Gfi1 loss of function deregulates 2 separable transcriptional programs, one of which controls the accumulation and lineage specification of myeloid progenitors, but not terminal granulopoiesis. We demonstrate that Gfi1 directly represses HoxA9, Pbx1, and Meis1 during normal myelopoiesis. Gfi1−/− progenitors exhibit elevated levels of HoxA9, Pbx1 and Meis1, exaggerated HoxA9-Pbx1-Meis1 activity, and progenitor transformation in collaboration with oncogenic K-Ras. Limiting HoxA9 alleles corrects, in a dose-dependent manner, in vivo and in vitro phenotypes observed with loss of Gfi1 in myeloid progenitor cells but did not rescue Gfi1−/− blocked granulopoiesis. Thus, Gfi1 integrates 2 events during normal myeloid differentiation; the suppression of a HoxA9-Pbx1-Meis1 progenitor program and the induction of a granulopoietic transcription program