4086 Back Gate by Tiburon
 
Tiburon returned to the Listener series this week with a pleasing but not too difficult puzzle. Corrections to misprints in some of the clues spelt out CYTOSINE, GUANINE, THYMINE and ADENINE. These are all constituents of DEOXYRIBONUCLEIC ACID, which was spelt out by the misprints in the remaining clues, in groups of four letters. The four names which could be seen in the grid by tracing out S-shaped curves were WILKINS, WATSON, FRANKLIN and CRICK, the four scientists who discovered the structure of DNA, and lines had to be drawn through these names forming a representation of a double helix. The title, Back Gate, was a play on AND (a type of logic gate), reversed, which spells DNA, and these letters (enclosed by the double helix) had to be highlighted in the centre of the grid.

Across

1 Coders [Covers] haphazardly emptied spreadsheet lines (6)
STROWS ST (First and last letters of SPREADSHEET), + ROWS (lines)
6 Soft mat woven in east [last] (7)
AFTMOST Anagram of SOFT MAT
11 A painter in play about island capitol [capital] (7)
HONIARA A + RA (painter) + I’ (in) + NOH (play), all reversed
13 Wind coming around cheers next [neat] catcher (5)
RIATA AIR (Wind reversed, + TA (cheers)
14 Longer [Conger] gasket protects edges of engine (6, two words)
SEA EEL SEAL (gasket) containing EE (first and last letters of ENGINE)
15 One stopping fruit store [story] supplier (7)
ANANIAS I (One) inside ANANAS (fruit)
17 Sextiles [Textiles] between Gemini, Capricorn, Leo, then Sagittarius, ultimately (6)
NINONS Last letters of BETWEEN GEMINI, CAPRICORN, LEO, THEN SAGITTARIUS
18 Uxbridge [Oxbridge] charity event, for example, terribly eager to include Western Cambodia (7, two words)
RAG WEEK RAGEE (Anagram of EAGER) containing W (weak), + K (Cambodia)
21 Exclude from lift [list] in newspaper limo having disembarked? (6)
UNROLL SUN (newspaper) + ROLLS (limo), with container SS removed
The reverse of the well-used “on board ship” device
23 With a metallic tent [tint] at Strathclyde, one faculty contains electric field strength (7)
AENEOUS AE (Scottish word for “one”) + NOUS (faculty) containing E (electric field strength)
24 Male digested intradermal lymph [nymph] (6)
MAELID MAEL (anagram of MALE) + ID (intradermal)
26 Having a loan [lean] advanced, penny black's secured (6)
ASLOPE  A (advanced) + P (penny) inside SLOE (black)
29 Short student's horse produces something like brays [brass] (7)
TUTENAG TUTEE (student, less last letter) + NAG (horse)
32 Decry [decay] weak European Communist (6, two words)
WET ROT W (weak) + E (European) + TROT (Communist)
37 Ocarina formed of pipes [popes] etc (7)
AARONIC Anagram of OCARINA
39 Bally game runs away (6)
COQUET [Dally] CROQUET (game) less R (runs)
42 Larne [Large] lake once further in extent (7, two words)
ARAL SEA ALS (old word for “further”) inside AREA (extent)
43 Eventually snag [snug] (6)
INTIME IN TIME (Eventually)
44 "Ah! Right to proceed!" is a popular cry [cay] for divers (5)
LARGO LA (Ah!) + R (Right) + GO (proceed)
Key Largo being a popular destination for divers
45 Floating talk [tank] that's drawn cardinals in two directions? (7)
DRACONE CARD (cardinal), reversed + ONE (cardinal number), not reversed
46 Property of a square [squire] number seemed odd (7)
DEMESNE Anagram of N (number) + SEEMED
47 Implements resembling putcheons [puncheons] entangled snakes (6)
 SKEANS Anagram of SKEANS

Down

1 Rattly [Rattle] note to play on a guitar (7)
SISTRUM SI (note) + STRUM (to play on a guitar)
2 Croon, say, [Creon] later introducing soul (6)
THEBAN THEN (later) containing BA (soul)
3 Ban [Bay] leather (4)
ROAN Two meanings
4 Successive pauses [passes] between players initially obvious without following score (6)
ONE-TWO O (first letter of OBVIOUS) + WO (without) after NET (score)
5 Ace [Ave] possibly, except straddling line (5)
SALVE SAVE (except) containing L (line)
6 Sikh band raised drink made with voddy [toddy] (4)
ARAK KARA reversed
7 Thailand journey for Scot results in his decline in wealth [health] (5)
TRAIK T (Thailand) + RAIK (Scottish word for “journey”)
8 In arms [army] slang, mortar or nickel-lined bomb (6)
MINNIE MINE (bomb) containing NI (nickel)
9 Conic [Comic] to hold water (7)
STAND-UP STAND UP (to hold water)
10 Component of suet [suit] that preserves flavour the second time's special (5)
TASSE TASTE (flavour) with the second T (time) replaced by S (special)
12 Appropriate, that is, for former girl's game [name] (5)
ANNIE ANNEX (Appropriate) with IE (that is) for EX (former)
16 One led up path [pâté] may be had here (4)
DELI I (One) + LED, all reversed
19 Pool [Pooh] buddy in bright costume (5)
KANGA Two meanings
20 Groucho employed extremely old term for cigar - segar [sugar] (4)
GOOR GO (First and last letters of GROUCHO) + O (old) + R (last letter of CIGAR)
22 Nit [Net] treatments limited to prime locations (4)
RETE The second, third, fifth and seventh letters of TREATMENTS (2, 3, 5 and 7 being prime numbers)
25 Corns [Morns] spike or turn gold first (7)
AURORAE EAR (spike) + OR, all reversed, after AU (gold)
27 Grid [Arid] section here's not hard (4)
SERE S (section) + HERE less H (hard)
28 Those leaving ensuring [enduring] impressions of film caught by those left without one (7)
ETCHERS ET (film) + C (caught) + HEIRS (those left) less I (one)
30 Blend [Bleed] once legume is chopped (6)
EMULGE Anagram of LEGUME
31 Before cocaine spread dope [done] (5)
ACTED A (Before) + C (cocaine) + TED (spread)
33 Plant lake [like] reed from NZ near European closed base (6)
TOETOE TO (near) + E (European) + O (closed) + E (base)
34 Those who rub [run] well, say, lubricate people (6)
OILMEN OIL (lubricate) + MEN (people)
35 Post [Poet], namely alderman (5)
SCALD SC (namely) + ALD (alderman)
36 Following Peru's appeal for help dash [dosh] for Colombia (5)
PESOS PE (Peru) + SOS (appeal for help)
The misprint “cash” for “dash” fits the definition but not the hidden message
38 Assumed came [name] from the Lower Jurassic (5)
ALIAS A (from) + LIAS (the Lower Jurassic)
40 On introducing a recipe, dine [done] lightly (4)
RARE RE (On) containing A + R (recipe)
41 Related by a bard [bark] (4)
KINA KIN (Related) + A